SO that's what I'm doing wrong! My horses are too small!
Well, on a more serious note, I'm doing the opposite...like some of you, I'm just 5 ft...until last year I was riding mostly huge horses of various breeds and up to last year the smallest horse I'd had was a 16.1 OTTB. He has been rehomed to a little gal for hunter/jumper shows.
Now, I have a 15.1 mare and just purchased an even smaller horse...well, ok...pony...at 13.2. I thought I would feel weird on the little pony, but to my surprise that little mare "feels right" for me. Granted I am an older gal and all I'm doing is just hacking about, showing days are over and gone. But, I think I'll really enjoy my "little ponies".
So, sometimes bigger is good at one point in your life, but sometimes small is great as well!
I am 5'8" and my horse is 18.2HH and I don't feel like he's too big for me for the most part.
-Everyone remembers you at the shows. "Oh, you own the GIANT horse?!" I guess that could also be a con
-He's my best friend and I can't imagine him any other way!
-Finding quality tack can be difficult. And expensive. I have had to order a few custom things.
-Blankets are difficult to find in 87"
-I like to trail ride a lot, and get hit by a lot of branches
-He only fits in my extra tall trailer and has to have two slots
-I expect there is more strain on his joints, so I keep up on maintenance (adequan & cosequin)
-We have spent two years working on getting the correct number of strides in lines, and are just now getting it. (For a while there we were masters at putting one stride in a two...at 1.10meters)
My QH was too big for me. Not ridiculously huge, but too big for me. It was mostly his width - he had the stocky QH type of build, but on a bigger horse. I could and did ride him, and enjoyed riding him, but he was definitely bigger than my ideal comfortable proportions. I had to use a long billeted XC jumping saddle when I jumped because having the girth and buckles under my leg made him just wide enough that my legs were stretched too wide to be able to hold onto him properly. He regularly jumped through my legs, leaving me still in position but just 3-4" further back. Not good for someone who wasn't super confident jumping.
I have ridden big horses (17+ hands) both over fences and on the flat, and been effective, but for my own horse that I'm going to ride almost every day I want something that fits me.
I'm barely 5'2" with my boots on and I regularly ride horses in the 17-18hh range. I mostly like it for the "wow" factor when people see me with my short limbs on a tall horse. :P I try to get photos of me riding the big ones. :P There are a few cons, like a long way to fall and adjusting the saddle while on the ground. At least they can be taught to hold their heads lower for bridling.
"A canter is a cure for every evil." -Benjamin Disraeli