Vic (Horn Dog) had some pretty good luck with his first Harbor Freight belt sander, but wasn't impressed with attempts to replace it until he got a Delta. It's definitely your call, but I'd go with the Delta over the Harbor Freight unless money's really tight (although Vic mentions that he still likes his in his "My New Delta Sander Rocks!" thread). Whatever you decide, good luck.

Here's an old sharpening thread -- one of the key tips seems to be that you should buy some inexpensive machetes to practice with before you try sharpening anything nice:
Sharpening Thread