A year or so ago the stats from a national IDPA competition had the stats on equipment used by the competitors.
Regarding reloading presses:
Dillon 199
Hornady 8
Lee 14
RCBS 9
It looks like where the question is asked has a lot to do with the outcome.
That would be my first comment. It all has to do with WHO you're asking. Any group will have it's own influencers and drivers which push that local population to favor something. I don't happen to know anything about Ultimate Reloader, either, but they aren't representative of ALL press users, of course. Maybe they have a lot of new loaders who've chosen the LNL because of local praise for it on that forum. Maybe they have a lot of OLD long-time users who have gravitated to that press because it really is more cost-efficient. Maybe Hornady buys tons of ad space there. Maybe something else.
I do know IDPA and the competition world is universally the "Cult of Blue." Again, there are probably several reasons which drive that. High round counts. Heavy demand on the presses + Dillon's reputation for customer service. The competition world's drive to get whatever's reputed to be the best: "buy once - cry once." Reputation of long standing, vs. a newer product that is less established? Some of it, I believe, is wanting to get whatever the "standard" is so you don't have to worry if that facet of your equipment is holding you back.
That might seem silly, but when you're competing against your fellows head-to-head with similar equipment, you tend to try to eliminate anything in your kit which is an outlier so that you are really testing your personal performance, rather than your gear. So a new shooter starts to become competitive in IDPA and puts together his gear package. He'll be told something along the lines of, "
Buy a Glock 19 (or M&P), buy a Blade-Tech holster, buy a Wilderness Instructor belt, buy a Dillon 550/650, buy Dawson Sights, Apex trigger...etc." because those things eliminate all question of equipment deficiency. It probably isn't that the up-and-coming shooter evaluated every press on the market and chose the best based on every metric (necessarily, anyway), it's that one day at the match he said, "
I need a reloading press...," and 37 people turned around and said "
DILLON" in unison.
So, all depends where/who you ask.