Have ProSport HALO series gauges (oil temp, oil pressure, and boost pressure).... which btw are called TOUCH in Metric form (metric Touch only available through the UK based EU distributor RSPEC and not directly available from ProSport in the States as they only sell the HALO which is imperial). I found Rspec very easy to deal with and very responsive with regards questions and they have a lot of other makes and spare parts etc. Their prices are also very good. Here's a
LINK to the Touch gauges I bought.
I picked the ProSport at the time because:
1. Can change colour (so can set the same as the dash amber/red colour and looks more "OEM" that way)
2. Can set audible warning at a certain value (e.g. have set oil pressure warning at 1.4 bar and boost pressure at 1.5 bar, to notify me with both alarm sound and LED indicator if oil pressure too low or boost pressure too high). I totally agree with Joe that you do not continuously look at gauges so that's why I like the alarm feature so even when not looking at them if a critical value is reached it will warn me).
3. Stepper motor with external sensors (so no "cheap" and unsafe solutions like bringing boost lines etc into car to gauges and very accurate and easy to calibrate if ever dial should go "out of zero".)
4. Good reputation and plenty of easy to get and reasonably priced spares and adapters etc (and for features they were very good value in the first place).
5. Oil temp sensor can be fitted on rear driver's side cylinder which runs hottest instead of using less accurate solutions like either a "sandwich plate" at the filter, or T adapter at OEM oil temp sensor site. (T at oem oil pressure site is fine as pressure reading unaffected).
6. Stores Peak value seen by the gauge (not essential, but turned out handy one time when had an over-boost situation)
7. Overall quality and features at the price point - think probably best value gauges out there (Way better value than DEFI... which are great quality too, but very dear for what they offer).
Few observations from owning them:
a. They are indeed very accurate (tested against both ECU sensor data and additional sensor gauges I had on my rally car).
b. Broke nib off the boost pressure sensor (lives under bonnet) when pushing rather stiff boost line onto it. I should have "steamed" the line more, but was impatient and used too much force. The good news for me was that it broke in a way that was very easy to fix (flush with housing so just drilled down few mm into housing, bought a nylon vacuum T-adapter from Halfords and cut nib off that to use as a replacement, and initially set with a bit of super glue to keep in place and then build up nice thick and wide supporting area with two component epoxy and stronger now than when new (see pic below). Now... had that not worked a replacement sensor would have been very reasonable in price at £22
LINK
c. The "touch" buttons that allow you to set the colour and alarms and read the peak values read by the gauge are a bit annoying. What I mean is that they are stuck onto the side of the gauge face with double sided sticky pads, and as a result you cannot just "push" against them when using the buttons and need to support them with a finger behind the button or else you'd either push them off their mounting point, or make them crooked. It looks fine if handled with care, but doing the settings is a bit fiddly because of the way the buttons are mounted. In all fairness you really do not have to change settings once set up to the way you want (unless you disconnect battery and need to put in settings again), so it is not something that bothers you often, but worth mentioning though.
Picture of gauges from my car:
