Bulbs, LED replacements, cross ref part #

[RedArrow]

I hear good And bad things about LED bulbs. Sellers swear it doesn`t hurt anything in your car. A friend of mine just changed all his bulbs; it is looking so much better.
Great experience or...is it risky business?
(Instr cluster, all switches` bulbs, headliner panels` bulbs, door safety lights planned, especially the annoying always (half-)dead license plate bulbs come in my mind... all to be switched out; Signals+tail+brake bulbs for added safety)

What is your experience?
This link shows original bulbs with part # AND their `new` LED versions, used in a (`86) 740.
http://www.superbrightleds.com/cat/l...40--/65-179--/
There`s a UK forum thread about it, but it doesn`t focus on possible bad results.
http://www.volvoforums.org.uk/showthread.php?t=177490
Ps. Will the `Bulb out` light go crazy? (-->remove the Bulb-failure relay?)