I really think this is way too subjective in nature. The main reason I say this is because it doesn't depend on the ROM so much as the following:
1) 3G or 4G speeds by the user
2) Reliability of the network the user has
3) Where the person is (maybe if (s)he moves from the basements to upstairs, the speeds will be faster)
4) What apps are open on the phone
5) Distance from laptop to phone
Anyways, aside from that, I'd like to point out hotspots are iffy on ICS ROMs, I've found anyways. Between the GB ROMs I never found a difference between any of the ROMs. On AOKP ICS I managed to get hotspots working, no noticeable difference in speeds over GB. However, on AOSP EB and Hellfire it would never turn on. Never tried Genesis.