The 5" tach was great, until it was stolen. Of course I have a Std. and thus no tach at all. I bought the 8 thousand RPM tach anyway, I'm planning on going B16, but the 10 and 12k tachs are overkill. Most the time you'll be using so little of the tach, it seems worthless. I've also seen people use a big tach on the dash, and then putting different gauges where the stock tach was.

You can also get a 3" or so tach that isn't so obvious, if that's a concern. The shift lights are great though... I used mine all the time. When I was on a 1600 mile road trip, I used it to mark the RPM of my top speed (for legal reasons) -- around 75 mph, so the light came on if I drifted over that... it was awesome, since I don't have cruise, this made the trip way easier since I didn't have to watch the speedo all the time. (4 tickets and counting makes you watch)

Remember, that money could be used for the rest of the gauges and other goodies, I'd stick with the stock one...

Jung