I love my TT G2 Pro 200. The tube style transmitter is very comfortable in the hand, plenty of different levels of stimulation, the charge lasts forever and the fact that I've had it for over 5 years now and not a single lick of problems with it. I train about 5 days a week and once hunting season hits, it's usually in the field ever weekend from mid August through January and then again it's in the mud and slop of muddy fields snow goose hunting in the spring. I've dropped it to the bottom of a pond, had it entirely covered with mud and its even found its way off the back of my pickup onto the road once and it keeps on going without a problem.
When looking into purchasing a new e-collar I was a little thrown off by the price tag but now looking back on it, the price of it and the build quality of it really have identified it as some of the best money every spent on training equipment.
I think most people that have one dog they are training will be fine with one of the entry level collars. For someone that has multiple dogs and wants to expand into a multi dog system and also need a lot of the features available on the higher ends will see the need to spend the extra money -
The range is often what determines the price - the farther the transmitter will reach out is going to add to the cost - In the end of it gives the correction when you push the button any of them will work - when it comes to how long they will work you get what you pay for -
Just my 2 cents
While all models are expandable to 3 dogs, the Pro versions are usually perferred for the range, the configuration of the buttons, and the flexability in stim levels. I just had to send in my pro 500 transmitter and used (tried to use) my Sport basic transmitter. Maybe because I was used to the other on a daily basis but I found the Sport model hard to hold and operate without fumbling for the right button. Finally borrowed a buddies Pro 200 to get me through the week!
I moved from a Flyway to the 500 to get the variety in stim levels at both a constant and nick setting which I found necessary when training a variety of different dogs. And I bought a single dog model instead of the the EXP. Hated having the EXP switch on the wrong dog when I needed it!