Ok, I am a 3 week old EVO convert, coming from a rooted Palm Pre with tether.
I have to admit before I updated 2.2 on my rooted EVO, I was running tether and the speed was a great, so after upgrading to 2.2 through XDA I assumed I would be fine. 2.2 is awesome, but I found tether seemed to be working great for a few days and then took a massive dive, I have the current tether_2_0_5-pre8.apk but I still average less than 100kb on speed which is pointless. I figured I would call sprint to activate the HotSpot to see if it was any better, which I also get the same slow speeds, sooo I take it, its an issue with sprint, but I reactivated my Pre on a different line to use Tether and it seems to work perfect, could it be sprint or the tether software?