I just made the switch from an Alltel 8130 to an Alltel 8230 7 days ago, here are some findings:

No L theme that I am aware of. The base theme has 5 icons along the bottom of the home screen and then all available after hitting the Blackberry button.

I normally had between 5-9 megs of memory free on my 8130. I have not dropped below 56 megs on the 8230. Nice to not have to worry about deleting SMS and phone logs anymore.

The Good:
Love the flip as a phone, feels a lot more normal when talking compared to the little candy bar the 8130 is. I have also noticed increased reception, in places where I would drop 1XEV to 1X and maybe lose service entirely I now have 2 bars of 1XEV. Very nice, however some of this may be due to the Verizon merger so take that with a big grain of salt. Bigger keys on the keyboard make it a lot easier to type with less mistakes.

The Bad:
They switch from mini USB to micro USB. Used to not worry about carrying a charger as I could always borrow someones camera cable and computer for a quick charge while out and about. With the new micro I have to be more conscious of how long I will be away from one of my new precious cables. Battery life seems about the same, get somewhere around 2 days of use with little to no talking on the phone. VIBRATE sucks! Don't know why they gimped the vibrate, it is significantly softer than the 8130. I have missed 3 phone calls in the last week because the phone was in my pocket and set to vibrate. I have just had to change my profiles to give an audio notification instead of solely vibrate.

Overall I am very happy with the switch and would not think about going back. Good luck with your decision.