Heliocol vs. Solar Industries for solar heating

I'm currently in the process of getting bids for putting solar in for my pool. Most of the contractors are pushing Solar Industries panels, and one is really pushing Heliocol. The sales pitch for Heliocol seems solid (less roof penetractions, allows for expanding and contracting better) but I'm really not sure if it's worth the price.
The Heliocol system will run about $5000, while the Solar Industiries will be about $4100.
Heliocol is 25 yr warrantee, with 5 year labor
Solar Industries is 12 year warrantee, with 12 year labor.

Solar Industries looks to be a little better for BTU efficiency.

I'm leaning on saving the money.
Thoughts?
thanks.

I have Solar Industries panels for almost a year. They seem to be OK. 25yr warranty sounds like rubbish. I'd go with the contractor you're most comfortable with.