3d's 48P ROKR Ultimate comes with showQ binaries, a must in the new mpkg applications we're watching lately, is fast and stable. This FW comes with the stock APMD. I mean, it has NO overclock.
Katze2 FW comes Overclocked. You will note a boost in your cellphone's performance, but maybe a lower battery duration (just
maybe, katze2 uses a well balanced APMD daemon).
In both firmwares you can improve rokr's performance making a swap partition. In katze2 you must make 3 primary partitions (fat16, swap and ext3). In 48PRU you must make 2 primary partitions (fat 16, extended -swap and ext3 as logical units inside of it-).
Is up to you to decide what do you want for your ROKR. If you use katze2, you can install the showQ binaries manually, if you want compatibility with the new applications. If you are gonna install 48P ROKR Ultimate, you can overclock this firmware with the OC mpkg a friend of mine made
None of these firmwares come with EDGE+quadband enabled, you must edit the seems or flex your phone to get this.