Great would be an understatement, though it was of course not without a learning curve as all new systems are. That being said, I essentially went straight from win ME to 7 when the first beta rolled out and been using some version of 7 ever since. I did toy with vista a bit but got frustrated with the compatibility issues with hardware causing instability and ended up going back to ME on that machine (Athlonxp 3800+) until the first beta of 7 came out. I still use windows 7, and after having briefly experienced 8 8.1 and 10 on new laptops (now upgraded to 7) I can honestly say I will be using windows 7 forever. If such a time comes that it becomes so tedious to even get internet browsing and email working, as had happened on ME, then I will just move to linux.
Comparing to other os's (windows) 7 is faster, looks nicer (except vista which looks just as nice) and runs smoother, and on a wider variety of hardware than any other windows.
It also doesn't have the hardware issues that plagued both ME and Vista, and provided you omit the telemetry KBxxxx updates doesn't have the spyware stuff that newer windows has.
so to summarize, fast, stable, and compatible. the compatibility mode for older programs works pretty well most of the time too.
I've had it on old and new hardware alike, from the Athlonxp (beta builds) to a relatively modern fx9850 with r9 390x graphics, and pretty much everything in between with no issues.
I would recommend 7 to anyone very highly.
The only real complaint I have is there seems to be no way to get certain old games (specifically Mechwarrior 3 and pirates moon) to run on 7 that I have found, so I have to keep an old Athlon xp machine with ME on it set up for that game. other than that, I've had no issues with 7 whatsoever.