Personally I see no big difference between 8-max and 9-max MTTs, but if I have to choose, then I slightly prefer 8-max. It makes the tournament play just slightly more hands per hour, and it allow you to participate in slightly more hands (higher VPIP) as well. And basically this is, how you find edge in tournaments.
9-max MTTs with regular blind speed like 10-12 min can often be painfully slow dealing only 30-35 hands per hour, which is almost as slow as a live poker table. This mean, you often have had very few chances to get involved, before the blinds go up, if you want to play a reasonable preflop strategy and not just be another fish limping in with K5 offsuit.
I guess, poker sites are just experimenting and trying to figure out, what works best. Interestingly 888 Poker went the opposite way and got rid of most of their 8-max MTTs, when they recently updated their MTT schedule. I would not consider this a big deal either way, and certainly not a reason to not play on a particular site.
Obviously, we are different, I see huge difference between 9max, and 8max, also obviously I prefer 9max, the play, the results, profit, everything is better for me there, as I play mostly that for 10+ years, and if you change it to 8max, there is a leaking....
And of course, you are right, 9max slower, but I have the opposite opinion, I can get involved more hands, as the blinds don't start to eat my stack in the first 3-4 hours at least, meantime the plenty stupid blind structures on acr, exactly were established for that reason, so you are forced to play by random hands on 8max, especially the 40 blind level 6 min tourneys, basically, you are short stack in the middle of the late reg period, what is pretty nuts... so it goes full
gambling, the re-seating is insane there, as well, so blinds just eat you very fast. not much a poker. From my viewpoint, it is the same on all blind structure, as they don't have deepstack tourneys, except the big ones, like venom, nothing on micro, low even on medium level....
And I play most of the times 4-6 tourneys in the same time, so it is okay for me, that is a bit slower, I have just tried, with this 8max, I can play max 4 tables, same like 6max, fast because they must be fast, if they dont want to go to the flip stage early, as the blinds start to hurt your stack after an hour, basically the plenty turbo and hyper became unplayable for me like this... not so much turbo and hyper out there on any site with 8 or 6 max, now they changed all to that, and let's be honest, acr's tourneys 50%+ are at least turbo...
I heard good things about 888, because of restricitions, I am not allowed to play there since years, I just hear about this change from you, would be really great to play on a site, where the opposite happens, and all 8max goes full ring, probably they have the 30-50 daily suitable tourneys for me, nowadays....