Dan,
Those numbers about 50% of the pool area etc are almost meaningless in my opinion, because there are too many variables including user expectations. What I can say is with my 4x20' Fafco mat I've measured the heat output in the range of 20,000 BTU/Hr in Northeast PA. Again, this is highly variable and dependant on sun, sun angle, air temp, wind velocity, water temp and flow rate etc. Anyhow, your 24' pool has about 100,000 pounds of water give or take. 1 BTU raises 1 pound of water 1 deg F. So, at 20,000 BTU/Hr you can get an additional rise of 1 degree in 5 hours. Doesn't sound like much but it's free. I would also consider diverting only part of the pump flow to the solar if there is an easy and visually acceptable way of dumping the solar output right into the pool. I have two heaters that dump via two hoses under the diving board. Keeps maximum flow on the system and I maintain about 10-15 gallons per minute through each heater. There is really no need to ram the entire pump output through these things although that's the way most people configure them.
Hope this helps.
Al