It depends on what you want to use it for. I have no issues with speed on my thrive, but I use it for mostly consumption (reading and watching movies). I love going to a hotel and plugging in a regular HDMI cable. Best of all, I love that I can replace the battery for another 6 hours of run time (the Toshiba replacement battery was like $25 on amazon). However, a word of warning. I got hosed on the ICS update. For whatever reason, my tablet does not see the update, even though there should be an update available.
If you think you will need the extra speed, you may want to go with the Excite.