I ended up buying BeeJive, so now I have that and IM+.
Don't know which I like more, but at the moment I see nothing that makes one better than the other.
Does IM+ Support sending and receiving images/voice, can you use your keyboard landscape?, how does the notifications work for it? is it fast/accurate, you able to log in for 24 hours on your service?
Test all of those and thats the best way of seeing which one is best