There's been a few "gens"... which ones in particular are you looking at (link)?

Personally, I didn't get the JBA's until the most recent gen (6.7) because their previous arms were designed around their coilovers and would cause the knuckle to hit the strut on non-coilover lifts. Although if I had the previous arms I probably wouldn't be inclined to swap them out for the new version, that was enough to prevent me from spending almost $500 on a new set of arms. Unless you're getting a really good deal on the older version, i'd get the new ones.