I'm having two issues here.

First is with the Google Voice app for Android itself. Ever since i installed it my phone has been unbearably slow and unresponsive. Has anybody else experienced this? Is there a good system monitor / task manager application i could install to see if it is in fact Google Voice slowing things down or something else?

The other issue is with the service in general. There seems to be a significant delay in conversaion. When i call people, they have to say hellp twice, and when we're having conversations, there is a noticable delay between when one of us says something, and the other hears it.

Google Voice service for me certainly isn't always perfect (occasional line noise and once the sound broke up into digitized-sounding bits), but I haven't experienced the kind of delays that you are talking about. Others have though:

http://www.google.com/support/forum/p/voice/thread?tid=1cae3ebc08334667&hl=en

The strongest evidence that this is a problem with Google Voice (and not some other link in the chain): "last night i was about 5 minutes into the conversation and then just all of a sudden we heard a "click" on the line and then the delay started to occur."

It sounds like this may be a problem that Google has to fix on a region-by-region basis.