Edit: Whee, bumping an old post. But hey, while I've typed it all out, might as well leave it, in case anyone's looking at a 2100Z these days. Especially since no one responded back in Feb.
Can't help on the 2188CL, but I have a year-old 2145US (Athlon 2400+ and 60GB drive are the main differences in mine) that I've been happy with. Fit my needs at the time very well, since I needed something on a budget, and the Compaq was the most inexpensive yet still decent-seeming laptop I ran across. I've been really happy with it as a budget laptop for general-purpose use, though we're considering replacing it (because our needs have changed, and I've "outgrown" the 2145, not because of any issues with it).
The 2400+ processor is pretty zippy (you'd have a 2500+, so even a tiny bit more speed). It won't break any records, but for general-purpose use, it's definitely very good. It's a 4200rpm drive (at least in mine), but again, for general use, having slightly slower disk accesses aren't really going to slow you down noticeably. I even game on this laptop, and one of my only real complaints is that the integrated video chipset with its 64MB of shared memory isn't sufficient to run newer games in high-res. However, it's more than enough to get you running in low-res modes. It's actually performed better than I would have expected.
Overall, if you're on a budget, and looking for a good value, it's a really good laptop. I have complaints about it, but it's all just because I'd like it to do something it wasn't designed to do (and I didn't need/want to do when I bought it). Things like game at high-res, and hook up to our rear-projection TV, and stuff like that. And really, even on those things, the Compaq tries its hardest, and does do a decent job. People may hate on Compaq, but I've really had no major issues with mine, I'm just planning on moving up the chain.