I'll try to have an answer for you by the end of the day as I have ScanXL-ELM and PCMScan installed on my laptop, and I can compare sample rates with the "better" software.
Tactrix 2.0 is supported by Binary Editor, but I don't have one so no comment on sample rate. EECtuning.org is a great place to ask, IMO.
The Innovate gear claims 12 samples/sec on up to 16 simultaneous channels. That's fast enough to tune off of. I have an LM-2 coming to verify that claim with, although I do not doubt it.
Care to share any .xdf's you have for OBD2 GM stuff?