OK, just my 2 cents concerning Cobb, MHD and JB4, without current in-depth research:
I bought my Cobb AP 3 two years ago. I believe the product is quite mature and failsafe with its original ECU backups and that there is not much left to improve within its scope as a map flasher and parameter monitor (OK, I would like to see an option for OBD readiness modifications). And there is still much space for own interventions with Access Tuner Race. So nothing to complain for me
MHD is certainly a more modern and cost-effective option for new adopters, but I didn't keep track if it would really better suit my needs than Cobb AP. I simply do not need it.
When I bought my Cobb AP, I also considered buying a JB4. But I did not like its approach to tamper with the car's sensor values and that there is additional hardware that needs to stay in the car - but this, of course, is only my opinion.
Best regards
Mick