I started on suretype and it is really really good at predictive input. Compared to T9, there's no comparison. However, my biggest complaint with Suretype is the amount of variations it tries to remember. It slows your typing down a little, and can mess up your messages when you're not paying attention (Suretype gets so good, that you do stop paying attention to what you're typing when you shouldn't, cause there are legitimate english word variations can make your message not make sense at all)
Other than that, Pearl and Suretype are probably the best phone I've ever owned. I have Pearl for personal and 8703e for work. I like full keyboard, been debating the Curve for personal use, but I know I'd miss the form factor of the Pearl... Also, my fav feature of the CDMA Pearls is that they'll have 3.5mm headphone jacks... That's also making me debate going to the Curve. I have a GSM carrier (Rogers) and the only 3.5mm BB are the Curve and 8800 (i think). I have a pair of really nice headphones that I'd love to hook up to my phone for listening to music, movies, etc.
Anyway that's my two cents. Good luck with your decision.