Excellent call on avoiding M-Audio. I've owned both the MT2496 and MTII and they both really suck for what we do and even though they're significantly less expensive, they end up being a waste of the $180 (IOW you're better applying that money to a higher priced recorder than trying to bandaid this thing to work for you), mainly because of the internal battery situation, but there are various other reasons that have been discussed in numerous other threads.
I now have the Sony D50 and I can say that, as much as I hate to admit it because I'm not much of a Sony fan, the D50 is a really great portable recorder. On the minus side...higher initial price, its digital input is optical only (no SPDIF), and proprietary flash media (unless the internal 4GB memory is sufficient for you, you must purchase Sony ProDuo flash media). On the plus side are the all metal construction and really solid feel, a nice feature set and menu set, no real design weaknesses that I've identified, it runs FOREVER on a set of four AA batteries, and all metal construction. Did I mention that this unit has all metal construction? Actually, I think as far as features, I like the 20+ hour run-time as much as the all-metal construction.
If SPDIF is a requirement for you, then the next best recorder to go for, IMHO, would be the Marantz PMD-661, but now you're up around $600.
If used is an option and size is not, there are some great deals out there on the PMD-671 for less than you'd pay for a 661.
Working up from the lower end, these are bitbucket options that I know of.