A look at a couple of the training pants, the Pull Ups.
Pampers v Huggies As the main two contenders, this is what I've found from using both for a while each.
Pampers - What I liked about these, they had plenty of blue "wet" indicators on the front of them and also they were slightly more roomy, so easier to actually pull up like a pair of pants. That was it and both of those had flaws to them.
The blue wet patch indicators never actually disappeared to show the nappy was wet, which they were supposed to do. Being a bit more roomy meant that the pants came off with the trousers very easily, which is not what you want if you've got a poop to deal with.
The biggest problem with Pampers though, the tear away sides didn't have a velcro like fixer to them, so if you had to change them in public it became a major hassle as you'd have to take the shoes and trousers off, you couldn't simply whip on a new pair like a regular nappy.
Huggies - The best thing about these were the velcro like sides, they came apart and stuck back together really firmly, making them very convenient to change when on the go.
Personal preference was the Disney characters as well, though that's no reflection on the quality of the nappy, but the wet indicators did actually work on these so you wouldn't find a bowling ball size nappy all of a sudden. These nappies were a little tighter than the Pampers, so were a little tougher for the little one to pull them up on her own, but it did mean they stayed up when you pulled the trousers down which was nice.
Over all, having loved Pampers for nappies in general and not liking Huggies, Huggies were the big winner this time, being much better product. The major flaw to both of them though, as they aren't nappies, they don't have proper side stickies to wrap the nappy up in case of a smelly poo disposal, which isn't quite so fun and also the gussets aren't quite as large as in regular nappies so they might spill a bit of baggage if the kid is moving around vigorously with a large load in their pants. You also do not get as many in a packet as you do for regular nappies, about 60 for $20.
Because of that I really do think they are a waste of time to use when your toddler is first starting out on the path to potty training and you might as well stick to regular nappies until they are well on their way to being able to use the potty or the toilet because once they start on these they probably won't want to go back to nappies either.