http://www.treoonline.com will have some info on them. As far as personal experience, I'll let you know Saturday as I am switching out my 3 CompVr 12"s sealed for 2 Treo SSi's ported.
I'm not a pro by any means so is far as what specifications mean I couldn't really justify it. But basically they were redesigned and are more durable and handle more power. The SS's handled 500w RMS and the SSi's handle 750w RMS. However, I have seen people putting well over their rating in either case. Are you getting them new or used. If new, from a dealer?
hey cavi what dealer did u get those ssi from ? i call them and told me the collest dealer in ga was in bama and if u can pm me their# or website of yourdealer if they have one