I've only used the SlideIT keyboard for a day, but I already like it better than Swipe.
I hadn't used Swipe for months, because it would spew gibberish if I swiped over letters it didn't know how to handle. SlideIT handles that situation by (literally) saying "??". At first I wasn't happy with that, but now I see that it's a lot better than churning out nonsense if I miss a letter in a long word.
It seems to be more responsive on my low-end phone. Though I need to see if the slowdown I'm seeing now is due to the skin I d/l'd, or if it's due to other factors.
It's still got glitches, but I'm going to get rid of Swipe (it's a system app, but I can back it up and delete it with Titanium).
While I'm at it, I may get rid of Better Keyboard 8, too. I only used it when I had to avoid the CR-send issue of Graffiti, but SlideIT works just as well (or better) in non-sliding mode. The skinning on SlideIT is better, too -- BK8's skin has ugly gaps in its graphics, and I never heard back from the devs when I wrote about it (unless I just dreamed that I sent a note).
Plus, even though I paid for Better Keyboard, I can't get updates now that it's been yanked from the Market. That would make Better Keyboard the first paid app I've yanked (though again, Titanium Backup makes the jump a bit less daring).