Had a perfectly operational X-9 shifter from 2005 ripped off the handle bar in a crash. X-5 is the closest 9 speed modern replacement. Is the X-5 now as good as X-9 was then? or should I check out e-bay/trade-me? also would I be right in assuming it's compatible with an X-9 derraileur from 2006ish?
Should be compatible but probably not as comparable in terms of materials etc. X5 will probably be more plastic etc. not as crisp.
Not sure how reputable but plenty of X0 about
https://www.amazon.com/SRAM-Mountain-Trigger-Shifter-9-Speed/dp/B000VSY660
http://www.ebay.com/itm/SRAM-X0-Mountain-Bike-Shifter-Set-3x9-Speed-Flat-Bar-Trigger-Shifters-Carbon-XO-/252676939477
Also probably worth a wtd ad, had a few till I left the UK
X5 stuff is nasty but it works.
SRAM have been slowly moving spec levels upstream for years.
Your 2005 X9 shifter will have been equivalent to at least X01 in new money.
If you need to use it, the modern X5 9sp shifter will be fine with your X9 9sp RD, it will just feel horrid.