OP, I've had the Rusty's long arm kit for going on three years now and don't think i could be happier (got another friend who's had his for a bit longer and he loves it too). I've had nothing but awesome experiences with Rusty's products and customer service. I honestly have no idea what every one has it out for him and his products.
I've heard that the TnT y-link kit can some times bind up and then unload quite violently making the whole front end jump... That would be my only concern. But i do agree that the TnT belly pan is better, where as Rusty's kit is just a cross member leaving it up to you to get a t-case skid. The rough country kit looks pretty nice but is pretty new so there isn't much experience or knowledge about the kit.
Over all though, i honestly think that for the money a good long arm set up is one of the best things you can do to your jeep. On and off road, the long arms will ride much better, give WAY more flex, and improve your vehicle's capabilities.
Good luck with your shopping!