I have a 4 year old 2000NC and a year old 1200NC. I use the 1200 more because I like the small transmitter and the fact that it fits on a lanyard and due to its small size is easier to hide from my one dog that is very transmitter wise.
From everyone I know that's used both the Dogtra is a little hotter than the TT so it's wise to figure out the levels that work on your dog and if you've used TT you may need to use lower levels with the Dogtra. My 2000 holds a charge a long time, I only need to charge it every 2 or 3 months. THe 1200 needs to be charged every 7 -10 days with regular use. Another thing I've learned about them (this is probably true for any collar) is that extreme heat or cold shortens the charge life so it's best not to leave them in the car or barn.
Their customer service is excellent, they go above and beyond. I had to send my 2000 in once and their turn around time is fast. For my 1200, my Thug Chessy pup got ahold of the lanyard to the transmitter when it was on top of her crate and pulled it inside and gnawed it up--she ate the antenna and continuous button off and crunched up the casing pretty good. I called Dogtra about getting it fixed and since it was still under warranty they fixed it at no charge! Now that's what I call good customer service; I'm sure their warranty was not designed to cover a teething 10 month Chessy.
It's a very durable product too. Shortly after I got the 2000 I dropped the transmitter in my pond. By the time I went up and got a net and fished it out it had probably been under water 45 minutes. Dried it off and it never missed a beat. (Can you tell I'm sort of hard on my equipment
) I give Dogtra a big thumbs up.