Okay I'm gonna have to disagree with that. I don't know what bee got in your IT guy's bonnet, and while he might have even had a
tiny sliver of ground to stand on for the first month or so after 10 came out, whatever he believed is simply false at this point.
Yes, Windows 10 takes a bit extra work after installation to get it running smooth, but at this point my Windows 10 machine actually runs way better than it ever did under 7, with only minimal UI changes to show for it (since I disabled the snoopy things/etc. in the first half hour after installation). Yes, it will require an extra 30 minutes of setup when you first run it to disable/alter some of the more questionable defaults, but that is by no means a strike against how it runs afterwards. Are there still some problems? Yes there are, but 7 certainly has issues still too. And worse than vista? As if. From my personal experiences it's neck and neck with 7 right now once you get past the first 30 minutes after installation (which is less time than it'll take you to finish installing the programs you regularly use), with the previously free 6 extra years of support due to 10's younger age definitely helping tip scales in it's favor.
Course if you've waited this long then the question is kinda moot now since you managed to outlast the duration of the free upgrade offer regardless; now it would cost the standard $100+ to upgrade, which is definitely a good reason to never upgrade windows at all, regardless of how good/bad the newer versions may be.
(Yes, I realize this is the hate microsoft thread, but when you start posting things that aren't necessarily true [and aren't even a microsoft vs somebody else thing] I'm gonna respond, sorry
).