Had mine a while and still finding it very useful and portable (I'm typing this on it in Turkey).
As for the slowing down, I get it occasionally but I use Advanced Task Killer to free up memory when it does.
I also read that the S/W is available if you know where to look, and you can install Google (Play) Edition onto other Android phones too. I take your point on them not being 'Nexus' and in all honesty, they are so expensive anyway, I'm not really sure what their market is. I was looking to upgrade my 3GS and couldn't really see myself affording an iPhone 5 hence looking at alternatives. Think I'll just save up for the 5.