Moving from a desktop LCD to the laptop is just a huge disappointment every time. Like you said, the brightness is the main thing, and I don't think that will be significantly better on the Al.
(or rather -- even if it comparing the Al side-by-side with the Ti, the Al looks better, it will still look horrible compared to your ACD.)
Just put away the ACD for awhile and eventually your eyes will forget about it... I found my powerbook displays wonderful for years, until I got a desktop LCD...