So far, my experiences with VC++ 6.0 have been positive. The only source change I had to make was to un-define some of my favorite typedefs (INT32 and UINT32), as they're now defined in the standard headers. I'm still trying to figure out why they started defining an INT32 and UINT32 type. They're also defining INT64 and UINT64, but they don't finish the job and define (U)INT16, or (U)INT8. I presume it's some kind of compatibility thing. I never understood why folks don't use integral types like this from the get-go. I dunno about you, but when I define a variable, I set the integer's size based on the size of the values that it's going to hold, not the size of the system's machine-word.
So far, I like the new additions to VC++. It's not really a quantum-leap from the earlier version, like 2.0 to 4.0 was. It's just got a lot of little tweaks and new features that are nice.
Since I don't use much Win32, and no MFC, the name-completion business didn't mean much to me. The new "recompile and debug from this point" feature is quite cool. I haven't really had a chance to use it in practice, but I tried it on a couple of tests, and it seems to work. This surprised me --it seemed like one of those features that sounds cool, but isn't really feasible (like Borland's old claims that their debugger could do backwards execution). The wizard-bar seems like it could be a useful alternative to the class-browser, but it just complains that I have to do a "save" before it'll work with my code.
I don't know if 5.0 had this feature, but you can now attach the debugger to the executable when making debug builds (much like the old Unix C compiler does). They claim that it'll help for those pesky bugs that don't manifest when the program's running under the debugger.
The help is now built on MS's HTMLHelp engine, rather than that custom sort-of-browser that they used in previous versions. It works quite well, and it require that annoying "building index" book-flipping animation anymore. Since the help-files are now standard .CHM files, you can browse 'em outside the IDE, like you could with the old .HLP files.
On a completely different note, I've gotten some very cool original MIDI files from Joshua Schpok in exchange for the MS Joystick I was offering in the swap-meet. He's got a web-page here. If you've got a need for some bouncy little MIDI tunes for one of your games, you could do worse than to contract with him.