Better... not sure... it's different.
CM7.1 is based on Gingerbread, whereas IceColdSandwich is based on the latest version of Android... Ice Cream Sandwich. As it is only a beta build, some things are not working correctly (I believe that some of the more up-to-date versions of the ROM I have on my phone have more things working, but I have not been able to flash an updated version, as I've been too busy).
Once the official version of ICS has been released for the DHD, then the proper drivers will be worked on by ROM devs and we would see a fully working custom version of ICS.
I'm really waiting for the CyanogenMod dev team to release their next version (CM9), as I loved their last one. Once it is released, I'm sure that it will be better than CM7.1