I've had the glo-shift for over a year and they work fine and are accurate (i checked with a scanner hooked up) , but they are backlit only and can be hard to read in direct sunlight, but look awesome at night.
Also you can push a button and pick the backlit color at will, to help match your dash light colors.
The pyro works like a tach, no hesitation or lag time at all.
The boost gauge, I wish I could have gotten with 30lbs. max reading for a broader sweep, but it is still accurate to within a lb.
The trans temp no problems either that I can tell.
Hope this helps you out with which way to go.
If you have any specific ? about them let me know and I will try to answer it/them.
Good luck with which ever way you go.