I would like to know if someone has tried both of these items and what, if any, was the difference in sound quality. I'm thinking about selling my pro fire 2626 and using the money to get a focusrite 24 dsp and focusrite Isa one for a little more.
Never used Focusrite but I did have a Profire 2626 with external pres (Art MPA Gold and Aphex 107) and the external pres were almost always better. Sounds like you might be better off going this route, as long as you don't need the extra channels. Also, you may well end up spending more than you expected.