From 0.9 onwards, Transmission fell into a dark period, where usably stable versions were few and far between, with crashing, hanging, transfer speed, Leopard-specific and portmapping bugs, and more than one bug completely corrupting currently downloading (or previously downloaded) torrents. I think 0.9.2 and 0.9.6 were about the only reasonable ones in a lengthy bad patch. More recently, tracker scrape bugs and more portmapping issues have affected 1.x.

It was a real shame, considering how amazing 0.8.2 (the last one before the darkness) was. If you look at your peer list, it's not unusual to see users still staying with 0.8.2.

With 1.0.4, for me (and I realize it might not be the same for everyone) it seems like Transmission is finally back to its old glory. Stable, fast, easy to use. If you've been holding off on upgrading Transmission, particularly if you're a 0.8.2 user, have a look at 1.0.4 (by all means backup your current version before you do). I think you'll be pretty happy.