I figured I'd go all out and upgrade to 10.5.8 and change from DellEFI to NetbookInstaller.
I had a 10.5 install USB from last year kicking around and used that to reinstall OSX on the new SSD
(GUID journaled). I didn't realize this, but restoring a TimeMachine backup does not restore the system fully, i.e., I ended up restoring a 10.5.6 backup onto a 10.5 fresh install. Many things weren't working when I did this, but I was able to use software update as Airport still worked.
I decided to just apply all available updates at once. While this was downloading, I decided to prep the system by deleting dsdt file and /.dellefi and /extra. This messed things up a bit such that I couldn't restart properly, therefore doing a hard restart. No updates were applied.
Booting from the USB, using -x -v brought me to a safe 10.5 mode. I reapplied just the 10.5.8 patch, and it found the downloaded one from the previous step. Everything went to 'Running Installer Script' with progress bar close to done. It hung there for about 20 minutes and I just hard rebooted the system. Surprisingly, the system started up as 10.5.8, at which point I applied the NetbookInstaller. The next restart I booted off the SSD
(all previous times were booted off the USB stick). The system started up smoothly without any errors and several annoying bugs were gone too.
I applied the rest of the updates and now have 10.5.8+NetbookInstaller 0.8.3. Looks like BT
has to be fixed again in Terminal and haven't tested sleep yet. Haven't tested dual display yet either.
Overall, took about 4 hours for everything. 10.5 install took ~30m-1hr, TM restore took about 2hrs, downloading and applying the updates took another 1hr.
Hope this gives some people courage to dump DellEFI and switch to NI.
Forgot to mention that after I restored my backup my user password did not work. I had to start up with the USB stick and reset the password (option under Utilities) on the newly restored system. Here is also where you can manipulate the admin password if you like.