The only tracking system I have 90% or better trust in is Brightshare, believe it or not.
The remaining MGS:
Referback 80% (which is saying something!)
Integrity 80%
Fortune 70% (based on old system)
Casino Rewards 70%
Money Mechanic 50%
Vegas Partner 50%
32Red 40% (because of their aff backend, not because of the casino)
Casino Profit Share 30%
Vegas Affiliates 30%
Wagershare 30%
Referspot 20%
GSN 20%
Roxy unrated (not enough experience)
Every single one of them, including Brightshare, has a lot of work to do. But as far as tracking goes Brightshare’s appears to be the most accurate.
YMMV.