MzScheme vs MIT Scheme

["J. Reeves Hall" <reeves@earthling.net>]

I've used MzScheme quite a bit, and I've been fairly pleased with it.
However, as I learn more about the language, I am interested in what the
other implementations have to offer. Could someone please offer a few
comments on the pros and cons of MzScheme and MIT Scheme? At a first
glance they seem to offer similar enhancements to the language, though
MIT Scheme seems to offer a few more special data types. I'm not really
interested in graphics capabilities.

Also, why is it that neither implementation supports R5RS macros, but
rather a proprietary macro facility?

One last issue... DrScheme seems to use an exhorbitant amount of memory,
and makes my entire system (dual PII running Linux) run slowly. I have
128MB, so this shouldn't be happening. Any ideas?

Thanks!
-Reeves

-- 
(setq real-name    "J. Reeves Hall")
(setq school       "Georgia Tech, CS Major")
(setq current-os   "Linux 2.3.99-pre5 (SMP)")