When I was first looking for a laptop, I knew that being the professional-level computer user I was, I wanted a quality laptop. I had some experince with Mac OS and liked it and Apple had a reputation for quality, so I went all out and picked the MacBook Pro.
I didn't max out the memory, but I bumped it up from 1GB to 2GB and bumped the hard drive from 120GB to 200GB. The memory bump worked out great because it helps to have the extra gig when working in Photoshop or working with video.
The hard drive bump ended up less great because my speed was dropped from 5400rpm to 4200rpm which makes the otherwise speedy laptop seem sluggish when performing disk intensive activities. The extra storage is great though because of being able to partition a decent size chunk to Windows XP in boot camp.
Speaking of Windows, I will get that out of the way. I tried both Windows XP SP3 and Windows Vista Home Premium SP1 on the MacBook. Both operating systems seem to perform better than many competing notebooks of similar speed, but Vista seem to have more problems. One of the problems I encountered in Vista was the that if I put the MacBook Pro to sleep by closing the lid, if I opened it too soon it would freeze, never coming out of sleep. When the system did come out of sleep it took it longer than it did to initially boot the system, rendering sleep mode in Vista almost useless. Otherwise the 8600GT graphics worked well in every game from Halo to FEAR to NFS:Carbon to Crysis and Bioshock on acceptable quality levels.
Back to the Mac side, this laptop came with Mac OS 10.4 Tiger and it ran smooth as silk, but after upgrading to Leopard, it was a bit of a mixed result. Applications seemed to run snappier and the whole system seemed to be tax the hardware less, but the eye candy animations weren't as smooth as they were in the Tiger days.
I have been running the latest iLife suite on here and all of it runs silk smooth. Due to the slower hard drive speed sometimes iMovie 08 takes a while to build thumbnails, but otherwise it is smooth sailing across the board as well as good ease of use with Apple's usual intuative and elegant solution to complicated problems.
I had been running Adobe CS3 Design Premium for the longest while without a hitch and just upgraded to the new CS4 Design Premium. Since I haven't played with CS4 enough to get a good feel yet (but so far, so good) I will base this mostly off CS3. Photoshop CS3 runs amazingly well and is a DRASTIC improvement over CS2, especially on Intel hardware due to using rosetta emulation. I can get it to cold start in about 15 seconds and warm start in about 3-4 seconds. It is very responsive. So far it feels the same in CS4 and the new 3D acceleration in CS4 works fantastic with the 8600GT graphics and is smooth as silk to zoom and rotate images and manipulate 3D objects. Dreamweaver takes a bit longer to load, but is still fairly quick and snappy especially compared to version 8 running in rosetta emulation. It picked up on Safari and Firefox on my system. The rest of Suite I only use sparingly, but it seems to all run fairly snappy except Bridge. Adobe Bridge is really pokey and really makes my system grind, both in CS3 and CS4, so I try to stay away from using Bridge. It's really very strange why it does that..
Another app of note I have run include VMWare Fusion which does great for messing with Windows, new and Old, as well as Ubuntu. VisualHub converts video super quick. My 2.4GHz Core 2 Duo converted a 1.5 hour DivX file to DVD format in around 20 minutes. Instant Messagers like MSN and Adium work fast and as expected. Quicktime and VLC can play back 1080p without issues on my MacBook Pro. Also of note is I don't really use too many of the little built-in apps like iCal or Address Book as I have no use for them with Gmail and Google Calendar. The illumited keyboard is extremely handy as I do a lot of computer in darker areas. The LED backlit display is gorgeous and awesome for watching movies on and editing pictures on.
Overall I am happy with my purchase. The slow hard drive is the ony thing that takes away from this otherwise seemingly perfect laptop. The new one's apparently come with faster 250GB hard drives, so I would definately go that route if you purchase one. I don't really use mine as a laptop, but more a portable desktop, so battery life and heat don't concern me, but I do know if you push it hard it does get quite toasty