Update!

I just installed the trial of Resco keyboard pro. It is neat. In the end, I think it comes to personal preference though. To me, one is as easy to hit accurately as the other.

Regarding Resco: You have to hit a button to go to special characters. Comma, period, question mark, etc, are not on the primary keyboard. They are on the HTC Diamond keyboard, however. I don't like having to hit an extra button to get there.

Regarding HTC Diamond: Overall, my preference. However, Resco does have a cleaner look. It's appearance and smoothness is superior to the Diamond keyboard. Still, I need my punctuation.

I will keep Resco for the time being, and periodically check it out, to give each a full swing. However the lack of punctuation being there kinda hurts. I do like the appearance of Resco though.