I'm running a black MacBook 4.1. Intel Core 2 Duo @ 2.4 GHz, 2 GB RAM, 250 GB hard disk drive, bus speed is 800 MHz. It's about three years old in excellent shape externally. I treat this thing like a baby.
It used to run awesome, but now it's super slow at everything. I get the spinning pizza of death constantly. It takes a long time to boot up or load any program, even Safari and iTunes. iPhoto is terribly slow. The Internet doesn't work properly and it reminds me of a buggy PC.
I've formatted it and re-installed Mac OS X 10.6 (with all updates), and I've done the disk repairs process. As an iOS developer this is driving me crazy, but luckily I have an iMac to work on in the day which is fast. I'm ready to format it again, but that didn't work last time. After the last format, I copied back files from an external drive so maybe the offending files were hidden in there somewhere.
Here are the hard disk drive and RAM specifications. It is upgrade-able to 4 GB of RAM.
Hard disk drive: The Fujitsu Mobile MHY2250BH is a 250 GB, standard hard disk drive. Its burst transfer rate is 150 Mbyte/s. This is a 5400 RPM drive and comes with an 8 MB buffer.
RAM: two sticks of 1 GB DDR2 SDRAM, speed: 667 MHz.