LED's last a lot longer than any actinic/halide etc bulbs, so need replacing less, that's about as far as i can say knowledge wise. As far as i'm aware they're also cheaper to replace, but i use 8 Actinic bulbs in my exposure unit and they cost me £1.96 each to replace.
In terms of exposure quality/time differences i couldn't say.
The linked bulbs do emit uv. Actually saw them on a print supply shop as a replacement option the other day so i guess everyones got the same idea. Anyways, any reason these cheapo strands of LED lights couldn't work? They are rated at 420nm like the actinic bulbs and used for aquariums. 15 bucks for 16 feet of LED would probably get pretty pricey, I would imagine you would have to throw as many in there as possible. Adhesive back and made to be daisy chained. I called vastex about their LED conversion kit and they run around $5000 or so if I remember correctly. Plus they are only available for smaller units focused on textile printing. Just throwing ideas around, I need to go to sleep.
i think it really depends on what kind of light in the spectrum they're emitting, there's also high end guys that you can adjust what kind of light they're putting out, exciting stuff. i've been thinking of replacing my nuarc single point with an led single point for some time now, i figure if you can grow plants with them you can definitely expose a screen.