Advice on Pump Motors

OK, I have four basic questions, with varying degrees of elaboration, so I will try to be as concise as possible. Bear with me and thanks in advance for any and all assistance.

All in all, I need to replace both of my pump motors, the main pump motor which died yesterday and the pool cleaner booster pump motor which has been loud for the past year, becoming insanely loud as more time passes.

1. This is the easy one--the booster pump motor. I have a Letro/Pentair Legend, but as far as I can tell, whether Legend or Polaris or other brand of cleaner with a booster pump, they all use 3/4hp motors. Unless I get compelling reason otherwise, I will simply replace with the same. But in this day and age of ever increasing electric costs, was hoping to get any opinions on lowering the hp for cost savings. Any thoughts on running the Legend cleaner off of a 1/2hp motor?

2. This is the more involved one. Current motor on Challenger pump is full rated 1.5hp (1.5 hp, 1.5 SF) that is at least 14 years old--it could be older and probably is, as it did not look brand new when I bought the house 13.5 years ago. Yet, when I do the flow calculations, EVERY time they peg the need at 1hp. Knowing this pool was built 32 years ago and the propensity for PB, especially in North Texas, to oversize the pump HP, I shouldn't be surprised. What I have is a 24K gallon pool, no water features, no heater. The skimmer and main drain are apparently combined before the pad, as there is only one return back to the pump, 2" PVC. Then into the Challenger, then into a Triton II-140 sand filter that has max pressure rating of 100 gpm (overkill I know, but I got a helluva deal on it 6 mos used from some rich people that HAD to have a DE filter on their new pool, but I digress), then through the valve, then through Rainbow chlorinator, and back to pool. So, that has me thinking that a full-rated 1 hp motor should be just fine. Am I correct in my evaluation? Could I even drop to a 3/4hp and be just fine? With the change in HP, do I need to be concerned with changing out the impeller to match? Obviously I have no certain way of knowing, but my assumption would be the current impeller is sized for 1.5 hp.

3. Regarding the same Challenger pump motor, as I have been researching this online, I have seen the recomendations to go with either a 2 speed replacement motor or a completely new Intelliflow variable speed pump--for reasons of electrical cost efficiency. I am pretty much against the Intelliflow for cost reasons $1K approximately plus the need for a new timer/control system to operate it. I will not be in the house long enough to spend that much money. So I was pretty set on going with a full-rated 1hp, 2 speed replacement motor until I talked to a guy at the local Leslie's. Full disclosure here--I RARELY deal with Leslie's except for an emergency need. I find better advice here at Pool Solutions/Forums and better prices at the many reputable online retailers. But with temps topping near 100 degrees and no way to circulate the pool water until at least the main pump motor is replaced, the sooner I get this fixed the less likely I deal with bad water after the fact. Luckily, after high use on the 4th of July weekend and a couple of heavy rains this week, I shocked the pool pretty good just prior to the motor failing. But as we all know, you are always living on borrowed time when your pool water is not circulating in sunny, 95 degree weather, so this is pretty close to emergency time!!! Anyway, the guy at Leslie's said that the 2 speed motors are great up north, but not for down here where you should already be running your main pump 12 hours a day. Well, actually, I only run mine 8 hours a day currently, except the day of a shock or in rare freezing weather, and my water is always just fine. But he said I would only be wasting money buying the 2 speed ($50-$100 more upfront for the 2 speed vs. single speed motor) because the low speed would never be sufficient even running 24 hours a day and I would end up running the thing at high all the time. Anyone with opinions on this situation and single, two, and variable speed pump motors? Other than possible ignorance, he really had no "agenda" to sell me a single speed vs. two speed, as far as I can tell. He had both in stock and would have made a bigger sale on the 2-speed. I really like the idea of lowering my energy costs, but I am also a realist and if the 2 speed will not work for my situation, I don't want to pretend like it will. Also, I have 2 intermatic 140 timers, one to control the main pump and one to control the booster. The guy at Leslie's said I would have to replace one of the timers to control the 2 speed motor. My understanding is this is one way of doing things, but it was also my understanding that the 2 speed motors either have a switch on the back or can be adapted with a switch on the back to change between high and low speed. This would be my preference since if the low speed works fine for my general circulation purposes, the ONLY time I would go to high speed would be for backwashing. I am not too lazy to lean over and flip a switch once every 1-3 months. Believe me, I love automation, but not unnecessary automation!!! Input on control of a 2 speed motor vs. single speed?

4. Again, like I said before, I rarely trade with Leslie's unless I simply have to. That said, if I buy from them, I can get this fixed today or tomorrow. If I buy online, it will be later in the week since I will have to wait on shipping. If all things were equal in this case, I would buy from Leslie's so I don't chance letting my pool water get all out of whack waiting 4-7 days to get the pump running again. But all things are not quite equal. Leslie's only sells Emerson pump motors. My research indicates that those in the know regard AO Smith motors as the reliability standard and Emerson motors rate somewhere just below to well below in quality. By purchasing online, I can buy an AO Smith motor for the same as I can buy the Emerson at Leslie's. Being a big believer in haste makes waste, if the Smith motors are superior, I would rather wait. But if there is no appreciable difference in quality, certainly I would choose to fix the pump faster. Anyone have opinions to offer on the quality of the various brands of motors? Is there a difference or is it marketing and/or people being set in their ways on what parts they choose to use? I also found a brand made in California called Advantage that makes motors. Anyone heard of those? Anyone with input on brands I may not have mentioned?

OK, in my long and drawn out way, those are my questions. I hope, as is usually the case, the intelligent folks here can offer some good advice. And even though my own situation is front and center of my mind, I cannot believe I am the only one out there facing or soon to be facing these same questions and decisions. Hopefully others can gain some help from my long-winded post as well...

Take care all...

Paul