I can tell you right now that the 3mm ones did NOT last at all for me in my TSX... I'm not sure if its poor electrical contact or if they're just not made right. I'm also not sure if these anomalies I speak of with the 3mm bulbs apply to the larger sizes you're inquiring about, but they're likely to.
Even though they are the same size and seemingly the same shape as the stock bulbs, they didn't fit in my sockets too well. Not that this lack of fitting will also apply to your jag, but its more than unlikely.
They certainly aren't the quality you're looking for in terms of the statement you made about desiring quality bulbs that last, so if I had to bet, I would bet that you'll be taking your dash apart frequently if you get these bulbs.
One thing I know from experience is those two companies make a lot of cheap junky stuff...
I would personally recommend buying just a few at first to see how it works out. Those sites have a 30 day money back limit, so I'd hate to see you buy 60 of them, have a month go by, realize they are no good, and be stuck with them.
One guy on the TSX forum bought a bunch of 3mm component LEDs (for cheap) and some resistors, and he soldered them into the twist-lock socket contacts. They held up great for him, but it was a ton of work to DMM-probe every socket and solder.
Good luck with your modding.
