Just got my SPT boost gauge installed--on my steering column. I don't have pics (yet), but will post some after I take them.
I think the gauge looks nice (matches the rest of the gauge cluster), seems to work well, and doesn't seem to bounce nearly as much as I was lead to believe after reading this thread.
The gauge is lit when the engine is running, regardless of whether my lights are on. When the engine is off, the gauge goes dark and the needle rests at 0 PSI.
As for the mounting location, I choose to mount on the steering column for a more low profile affect. I didn't want this big gauge on my dash for other drivers to see.
There were a couple disadvantages of installing the gauge on the steering column, directly in front of the tach:
1) I cannot read the odometer without looking around the boost gauge pod to one side or the other--fortunately, I could care less about reading my odometer while the car is in motion, and have no problem looking around my boost gauge
2) the base of the boost gauge pod had to be cut to avoid overhang off the back of the steering column, since the gauge has to sit back far enough to avoid getting in the way of the steering wheel when making a turn
In my opinion, the advantages outweigh the disadvantages:
1) though I cannot read the odometer without looking around the gauge to one side or the other, I can now very easily read both tach and boost gauges at the same time with a quick glance--this is due to the fact that although the boost gauge sits directly in front of the tach, it is small enough (and the tach is large enough) that both can be read from where I sit, which is to say the boost gauge location doesn't in any way prevent me from reading my tach
2) with this "low profile" installation, nearby drivers don't see this big gauge sticking out of the top of my dash
3) in addition, this low profile location seems to solve the problem that some have mentioned about difficulty reading the gauge during the day--it sits low on the steering column and not high on the dash, so there is less sunlight reaching it making the backlighting perfect IMO
Overall I am pleased with the gauge.