There is an improvement over stock lamps for sure,however I found the speedo and tach still not to my expectation, so I fitted LED strips in those gauges and bingo lots of light ,however you need to open these gauges to fit them so maybe not an option for all folk as its not real easy unless you have done it before .
My 911 combo gauge works fine on the LED lamps I got from superbrightled.com so I added one to my standalone fuel gauge to good result also.

I have been considering swapping my gauge lights to LED as I have a hard time seeing my speedo and even the tachometer at night. My combo gauge is great. I would go with the LED vintage color I think.

LED bulbs that fit present instrument sockets:
These are the ones I'e sourced , sorry don't have exact ordering info,
but these work fine and weren't expensive.

Click to view attachment Click to view attachment

I used the LED instrument light package that Auto Atlanta sells and am very pleased with it. Brightens things up, but not overly so.