I don't ride any 'discipline'. I just ride. I do what I feel like doing on any given day and I ride in what is comfortable, fits my horse, and suits the job.
When I took lessons, it was in english saddles. When I got my first pony, I rode in a huuuuge old stock saddle that I swam in (I was 10) and went back to my ponies rump. The first saddle we bought was a Wintec 500 - because it was cheap.
That saddle has lasted me ten years and is still my comfiest saddle. In that saddle I have done: Dressage, jumping, polocrosse, cattle work, mustering, gameing, mounted games, trail riding, endurance, and just about anything else you can think of.
I don't think security is about the saddle - It is about knowing your tack. I galloped headlong downhill through rocks, rabbit holes, logs, long grass chasing sheep in my wintec and never missed a beat. Had you asked me to do the same in a western saddle? I probably would have landed on my head. I was used to my tack, I knew it's limits, I knew how to sit it. I am currently breaking in a pony in that same wintec.
As to what type of riding I prefer - When I was a bit younger, I was all about the SPEED. Mounted games, sporting, polocrosse, jumping fast. The faster the better. Our trail rides were 70% trot/canter, 25% gallop, and maybe 5% walking :]
I also always had an affinity for working cattle and other working disciplines. I was born on a farm and my dad is a farmer. I always loved helping him bring the cattle in, and I did it fine on my 11h pony and 14h arab.
Nowadays? I'm more interested in training than any 'specific' discipline. However I am a strong believer in every single horse I ride knowing how to move off leg, stop on a dime, turn on a dime, be able to gallop without going nuts, as well as work with a contact and in frame. Basically I want a horse I could do anything on.
When I compete nowadays I generally do ASH shows and campdrafting, as I still like a bit of speed :]
When I finally had money I got a custom made saddle - A stock saddle. It fits my purpose. it took me months to be as secure in that as I was in my wintec.
To me, it's all just riding. Except for roping, there is nothing I can't do in my english saddle.