The EC is quite new, and didn't get much use, while the other one is a bit older, but has been working well.
This is the 2-slot model, but it can house 3 cards.
Both have been used to work with Scope v.4.5 on laptops, with success. There's an obvious loss in terms of PCI bandwidth (when compared to an internal PCI) that lowers the performance in terms of RAM based processes (reverbs and delays, i.e..). However, for synthesizers, I have found out that the poly counts are almost the same, especially with the EC model.
PM me with offers, if interested. You can combine one of these with the cards in my other thread and have a portable Solaris synth way before the XITE and HW Solaris crowd do

Thanks,
T