I've also heard mixed reviews, personally I think the prices are a little high and they seem a little shady. They claim to be able to sex juvenile turtles and from what I've heard they send you a free RES, which I think is ridiculous because not every wants or is able to house a full grown RES.
Turtlesale.com is a blackeye on this hobby. There are so many more options available, especially since hatching season is in full swing right now........
I would never buy from them.
I think they're a little overpriced.
They also encourage the sale and purchase of those horrible little turtle island/lagoons. You can buy the lagoons alone or they have an option of selling the lagoons complete with 1, 2 or 3 red-eared sliders.
They don't cull, obvious from their two-headed and eyeless genetic defects they pass off as overprices "rarities".
I would rather buy from hobbyist/breeders in person or at conventions. If you have to buy online buy from known and respected breeders/sites.
Go to turtleforum.com for more info on turtles and feedback on reputable sellers/breeders.