Okay, so I know in Europe, pretty much EVERYONE trail rides English. However, here in America (at least out West, where I live), just riding English period gets you funny looks half the time, much less trail riding English.
That being said, my Aires is going to be primarily a trail horse for now, but I hope to eventually do hunter and English pleasure with him (just local schooling shows, nothing fancy). It was suggested to me by the trainer who is going to be breaking him for me that I break him English to begin with and just trail ride English. She even has an old English saddle with a tree that she's pretty sure will fit him (he's a Percheron/spotted draft cross, but he's only 2yo right now) that she's willing to lend me until I can get my own saddle(s). I really like this idea, part of the reason being that I have a shoulder injury which limits my range of motion and the amount of weight I can lift, so if I rode with a Western saddle, I'd have to always have someone help me tack up my horse (he's 15.2hh now and will likely finish over 16hh...his sire was 16.3hh and his dam was a Percheron, so probably around the same)...at least until I get my shoulder fixed (slow going with stupid state-funded health care).
However, I was talking to one of my friends last night and she made a statement that threw me for a huge loop..."You know you can't trail ride in an English saddle, right? It will hurt him." I was like "Huh?! Who told you that?" Apparently it was one of our friends who runs a boarding stable and rides mostly English. According to this friend, riding them English on trails will "wreck [a horse's] back because the weight isn't evenly distributed in an English saddle." Again with the big "Huh?!" So, I googled. Most of the stuff I came up with said that riding trails English is just fine and actually a lot of people prefer it.
So, I'd like to get some personal opinions/experiences. I would ultimately prefer to ride trails in an Aussie saddle (they just tend to fit my body better), but until I can afford a good one, I'll take what I can get. If I do end up riding Western, the owner of the stable has a huge tack room full of saddles that he loans out to anyone who boards there, free of charge, so technically I don't have to get my own saddle yet either way I go.