Bristol_Jonesey I think you'll get lower latencies with the MOTU, but I've been running a Focusrite Saffire PRO26 via Firewire since 2007 with absolutely no issues. The latency is perfectly acceptable (and this is not using a native driver - any new Focusrite models will have better drivers)
ChuckC I have a pro 40 and have been using it for about a year now. I like it a lot & have used it for around 20 projects. I am not really sure how everyone else used it but when tracking I am using hardware monitoring with the included Mix Control software which is virtually no latency. I can punch in drum parts so.... I am not hearing any latency at all? I want to get the OctoCapture too so I can expand my rig via ADAT to have 16 analog ins.