I have not cooked on the G-Sport but my Brother-in-Law has a built-in Tec infrared grill (not sure of the model) that I have cooked on several times. It is a very nice grill but there are a couple of things I didn't like. 1) It cooks REALLY hot - very difficult to get it to burn at low temps so we really have to watch everything and some things can be difficult to nail - like chicken breast. If I didn't butterfly them they would not have cooked right due to the high temps. 2) I don't like the closed grate as food and grease collect in the grooves and it is hard to clean.
Personally, I like my Weber Summit much better than the Tec. It is way easier to control the temps and can get it to a much lower cooking temp.
Just my opinion and experience with the one Tech grill I have used. We did install new burners and igniters at the start of the season and it did not seem to make much of a difference.