You are lucky I had been testing for 4 weeks about 6 weeks ago, I am already playing Horde on Gehennas and wanted to roll one alliance for the different quests.
I have been doing Census on Zandalar, Earthshaker, Bloodfang, Razorgore, both sides, even went through : how many items were on the AH and how it fluctuates.
As you say, Ironforge is ‘mostly accurate’ but some stats are off, simply because some realms have more casual players whom are not included since they are not included in raid stats.
Conclusion for me was:
Earthshaker would have been the best pick for Alliance, but I went with Razorgore because I wanted to be on the other end of the stick for once in terms of being on the slighlty dominated faction and I also didn’t want to contribute to making the balance worse.
Razorgore fluctuates somewhere between A/H 43/57 and 45/55% according to my statistics.
Earthshaker had a A/H 58/42% balance.
Zandalar is very good for Alliance but is getting worse for Horde A/H 60/40%
Bloodfang was also a decent balance but the population was getting a little too low for my taste. (Especially on Horde). A/H 58/42% ish.
Unfortunately I did not test any PvE servers so I can’t say anything about them…
I would really pick one of these and try them out, just don’t immediately believe every google result or reddit post you read about a server, there’s always someone with a bad experience on ALL of the servers available…
These are MY stats over 4 weeks, stats WILL change obviously.
Good luck.