For service, yes, IBM tops Apple. However, Macs are known to be reliable. With a mac, you won't have to take your notebook in for repairs and fixes as much as you would with a PC. Even though IBM is known for reliability, Macs are still *slightly* better in this department.
For heat and battery life, IBM wins hands down. The powerbook is known to get hot, or warm. IBM's, if anything, don't get more than lukewarm. Ever. Battery life in IBM's are also longer, however, 3 hours on a powerbook is still QUITE respectable.
IBM's generally have better screens than the powerbooks, so we'll just say IBM is better in this category.
this is always the toughest area to compare between PC's and Macs, and usually just leads to flame and death. Benchmarks are useless because Macs run different coding and programs. You can't run a program designed initially for PC to work the same way on a mac. OBVIOUSLY the PC will be faster in this respect. So lets forget and toss out those benchmarks. And comparing specs are totally useless too. A 1.67 GHz G4 is NOT NECESSARILY slower than a 2.13 GHz Pentium-M Sonoma. Think of it this way. Even though a Pentium-M has a slower clock speed than a Pentium-4, many of them still run teh same Benchmark speeds. Now, on to the comparison again. From what i understand from friends that own PB's and IBM's and such, the Powerbooks are snappier than teh IBM's, overall. They can multitask more easily, they have, generally lower load times, and are just overall, quicker. However, the IBM's are a little better for gaming, probably because of the video cards.
All in all, choosing what you want is really dependant on what you're going to use the notebook for. If battery life is more important to you, get the IBMs. If reliability and speed is more important, the macs are better. Really, its all about what you want out of your notebook.