I've been fitting the cs tcu to the standard cars since the cs came out. It is a simple fit and a 20 minute job to program the pis to the correct setting. Saying "the pis should be 4.5" is like saying "this bit of carpet will fit your house". You can't just dial a number in. You have to use the clutch thickness setting to get the best pis setting, and every car is different. Some customers of mine with this tcu run 4.1 withno issues. Others won't go below 4.9 without dragging in gear when hot. All I can advise is that if you can get a cs tcu for a good price, absolutely do it. It has the best software of the lot and set right on a properely working system your clutch wear can reduce massively. Oh, if your clutch wear is 77% you should get them to adjust clutch thickness parameter before pis, and that they should increase it until they start seeing revolutions on the input speed shaft, then shift it slowly back until it reads zero. Then set pis. This will mean that your clutch wear reading means nothing, but that's irrelivant as you will now get the quickest shifts and maximum wear from whats left of the clutch.