I have used both. For filling in places like for an old horse, really liked the Tacky Too. When I started having saddle fit issues on a new horse, I went wool felt.
Just got rid of the last Tacky pad and replaced it with felt. I am using one Impact Gel 3/4 inch on one horse, and a 3/4 inch Diamond Wool pad on the other.
I do have to say, the Tacky Too pads were easy to clean and lasted for many years. I have worn out a few wool pads, but will have to see how the Impact Gel lasts, only been using for about 6 months, just bought the Diamond wool pad. The Tacky waffle weave will break down...after about 10 years.
The Tacky Toos are easy to clean, I'll give them that much. The waffling seems to not hold up -- despite cleaning it frequently, the material is flaking apart on mine and leaving gaps. Maybe it was just really old when I got it (tack auction) and it was improperly stored. I've seen wool felt pads that are older than dirt and are still in excellent condition.
Wool tends to take longer to dry out once it's been sweated under. The Tacky Toos you can flip upside down so the waffling is exposed and it'll dry out in no time -- wool pads not so much.
I'd ask to borrow someone else's pad before you buy a Tacky Too for your horse -- I know one horse who absolutely cannot stand Tacky Toos (its probably the anti slip nature of it) but she's perfectly happy in wool.
I've used both, as well as a Wyngz western pad, and a couple of Air Ride pads. The tacky too was great on a very round arabxQH gelding we had - kept newbie riders straighter than a felt pad. If you're looking to fill in wither holes or adjust a so-so fit, I'd go with an SMX Air Ride, I've had good luck with both of these:
I won't use neoprene on my horses. Even with the weave *I* feel it's too hot, not breathable. I try to imagine which I would want on me, felt or wool or neoprene. Have one horse that can't tolerate neoprene, would heat him up (I had a neoprene girth) and would be raw and tender. Since then I started thinking about what would be more comfortable for THEM and not for me (such as cleaning ease of neoprene. I power wash my fleece pads).
I am going to get a wool pad because I think it would be even better than the fake fleece bottoms, because that is synthetic also.
This is only my opinion though.
I want a signature but I have nothing original to say except: "STHU and RIDE!!!
Wonderful COTHER's I've met: belleellis, stefffic, snkstacres and janedoe726.
I am also neoprene-averse. I did try a Tacky Too a few years ago, just to see if it might help a horse with a weird back. I didn't use it for long, as others have noted it has an annoying 'flaky' tendency. And, well, it's neoprene.
I use wool blankets, single or double, when thinner padding is warranted, if I need thicker padding I use this type from Diamond Wool:
If you want your wool pads or blankets to not smell like sweaty, dirty ick, you can spray them off with Veterycin or Bannix, just a light misting, and they won't stink.
I keep mine clean, by using a show-cattle blower to blow all the dirt off my horse's back before I put the blanket on. They get sweaty, but never gritty.