Mainly price, but I owned a Pro4X Nissan that came with the lower grade 4600 Bilsteins and I really liked the ride. On the Ranger at the time of purchase, the Bilsteins were like $389 for all 4 and the Eibachs were around $440. Probably splitting hairs as far as which is better and they offer similar height adjustments. I really like the Grabber ATx, had the original Grabber AT years ago. I mainly chose them over BFG's because they had a good rebate, the site (tire america) had them for 15% off and they weren't overly common at the time.Why'd you pick Bilsteins? I want to level my Ranger, well, I want the front 1" taller, so I was looking at Eibachs. After that I'm seriously considering some 17s with better tires.