I'm in the same boat. Don't love the standard display and will likely go a different route. I think I'm going to check out the Koso, see how it fits and looks and if I don't like it (quite possible), I'll sell it. My setup is that all my engine sensors are wired into the ECU and data will be available over CAN. You can still drive mechanical tachs through PWM output.
Not to make this a giant response, but here are the broad options as I see them for this situation, all with the intent of being road legal:
1) Motec SDL or AiM displays. About $3000 & $2000 respectively. If you have an ECU that spits out CAN and you have all your sensors wired into the ECU, this is an easy connection for all engine and speed parameters. Add turn & light indicators and you're good to go.
2) Run a standard mechanical tach and/or speedo to get you odometer for being road legal. Then add a Motec MDD (a bit dated these days) for all the CAN-based engine parameters. Add same indicators as #1. Add optional shift lights (which can be inside a gauge too). Examples are Stack ST700 tachs here.
3) Go full mechanical. This becomes harder with a fully CAN-based set of sensors. Duplicating with mechanical sensors is an option though, but then it's a bit of waste of an ECU.
4) Wire in a "carputer". This is another huge topic on its own, but I will likely take an Intel Atom PC with a CANbus input and write some code to display my ECU's data on a display. Total cost <$1000. I already have the plumbing running in emulation on Ubuntu Linux. There are windows solutions to this as well. See mp3car.com for a plethora of goods for this.
Overall, I'm big time on the fence on this still, but my latest thinking is #2 with a better Motec MDD (coming this year) or running a small USB display off the carputer. That all depends on how confident I'm about relying on a carputer for vital signs. As of now, that's low, so to be safe I'll probably do the following:
- Analog tach driven by ECU PWM, like Stack ST700. I just like an analog tach.
- Speed & odometer either digital in the tach or separate gauge, like Stack ST700
- MDD to have a reliable system for vital signs and warning codes
- carputer in the center console for the fun of it (I'm a geek at heart...)
The SPA gauge is interesting too, but I wish it were fully CAN based and programmable. That's the crux - CAN is different for every vendor and so the devices need to allow programming to your ECU.
This is also all dependent on whether it will fit on the dash, as has been noted... don't have my kit yet, so I'm going to get some measurements soon to allow better planning.
Tim