I just got the APR TCU tune at Waterfest last weekend. I feel like my car acted weird before the tune. There would sometimes be a delay going from Neutral to D (especially if I was on a hill). Let of brake, hit the throttle, wait, and then it would grab. Shifts when stock and stage 1 were smooth but the car raced into 6th gear in D and was useless in S mode.
The TCU tune is worth it. It is obviously intended for a tuned ECU and works perfectly with the Stage 1 ECU tune. There is a noticeable firmer shift when you are under a high load, quicker shifts and a faster response when using the paddles. D is nicer to drive in under all conditions, and S mode is finally usable. I literally didnt drive the car in S because of how it would hang onto gears. Now S mode is great and holds a gear when you want but will upshift at lower loads without sitting in gear till 4k+ rpms at very low throttle. I also feel like my car will stay in 2nd gear a little longer when slowing down to a crawl and then taking off again which I love. Before it would drop into 1st right when you wanted to take off again and would be in-between gears at the wrong times.
My current combination is running perfect and is a blast to drive. Smoother than stock, way more power, better MPG. I have no complaints. I will but going stage 2 within the next two weeks and I will see how the TCU tune does there. One of the main reasons I got it was to go stage 2 and not worry about slippage.