I've had the ABS ones on for about 10,000 miles and have had no problems with them, no chips or anything and they're nice and flexible.
They're very easy to fit, takes about 10 minutes including holding them down while the Marvin Medium (definitely the best stuff for sticking these on) dries.
There's no noticeable difference in light output of the headlights so they're the perfect size.
I paid 7 quid a set for 2 sets from a German seller on eBay, plus Ԛ£7 postage so Ԛ£21 in total, the sellers name was plastico_fantastico and I highly recommend him
One thing I've gotta say though is that they're too shiny and pick up fingerprints too easily to put on unpainted, you'll have to either paint them the colour of your car (IMO the best way to do it) or spray them matt black to match the headlight surround grilles.