Hey Red.
Started a great discussion here! Yes, I remaster old stuff as well. I think the trick is NOT to get too crazy with the enhancements, i.e. too much high-end and bottom-end, which get too easy to go overboard with.
But hey, there's no rule against experimentation! Right? Therein lies the fun in it all!
I think iZotope's products, especially Ozone 5, are wonderful mastering tools! I however use Adobe Audition for mastering/remastering, mostly; as well as Sony Sound Forge. But yeah, I need to give Sonar a try as a mastering/remastering tool.
If you really want to get crazy with remastering older stuff, check out the latest offering from Sony - "Spectral Layers Pro". Can do some really cool stuff with that.
If you want some REAL fun and challenges (and you have a surround sound system available), convert stereo mixes to multi-channel surround sound. That's my specialty!
Have fun, bud!
JT