Debating upgrading Intex cartridge to sand filter...

Was getting ready to order a couple more Unicel filters for this season when I saw that Amazon isn't stocking them right now. From what I can tell, the place that is selling them through Amazon is a pleatco dealer, so I don't want to purchase through them. I have found a source for Filbur cartridges at a very reasonable price with a low flat rate shipping. I was about to pull the trigger on those when the thought of a sand filter crossed my mind....

Will the filtration be that much better with an Intex 2650gph sand filter? (as apposed to my 1500gph Intex pump with skimmer socks on the over the wall skimmer). We aren't having any problems with keeping the water clear this year (thanks to the Unicel and the K2006!) but I am needing to rinse or swap out the unicel cartridges after less than a week due to low flow (I think from all the cotton that is still making it to the filters, or they are worn out - used for about 2 months last year)

Each morning I have to rinse the skimmer sock and basket of cotton, small insects, and leaves... we have a heavy bather load (5-10 kids / day & 2-6 hours/day), and get a lot of hair in the pool with the girls accidentally pulling out hair while taking their goggles on and off etc.

If you have upgraded to a sand filter, have you kept your over the wall skimmer in place in addition to the sand filter? (I see no way for the other surface leaves and such to make it into the pre-filter basket that is part of the sand filter setup).

Thanks for any advice!