Gents with BC coils, you're saying that BC coils at a lower stance still rides better than stock air suspension at stock height?! I"M SOLD! lol

I would be really surprised that a coil over suspension would deliver a better ride than an factory height air suspension. This is a highly subjective evaluation. Coil over may handle better in the twisties but ride comfort? Highly unlikely ..

BC Coilovers rides better.....maybe because his old Air suspension wasn't functioning correctly?..........I think?:dunno:

At stock height on the air ride vs lowered on the BCs id be hard pressed to say its a better ride especially on bumpy roads. Air will glide more over it IMO. Im not sure if BCs come with different spring rates if they do and you have a softer version and dampener settings set really soft then maybe.

I think one of the major things that have to happen here is the person considering the change to coil overs ought to ride in members vehicle to determine if the set-up is delivering a rid suitable for that person. I have been in a number of coil over equipped vehicles and it really depends on springs and dampening to make a difference. For instance a number of my fellow enthusiasts have coil over on their E39M5 and one of three that I rode in rode really nice like a factory setup but with better handling. The other two were stiff like a go kart and there is no way I would be able to live with that set-up on daily basis. The difference between the E39M5 with coil overs that I liked vs the other two simply was the spring rates and dampers/dampening set-up. With regards to the E53 if the air suspension system is functioning correctly and dampening as designed then the ride is acceptable to many. Many of todays cross overs and SUVs use full air suspensions to achieve a balanced ride and load control. So these systems have their merit but when they begin to age and fail then the nightmare sets in. If the air suspension in the E53 is failing, you do not want to waste time chasing the problems and you want a reliable alternative then perhaps the coil over is the way to go. Its a set it and forget it system.

Bc coilovers
 

I'm on bc coilovers since shortly after I bought the x5. Susp inactive would come on at highway speeds with the air.
Bc coilovers handle very well.
My opinion is i like them better than the stock hight and springs.
My dampening is mid to hard considering I'm low and I don't want body roll and tires to rub fenders.

I'm on stock 18 inch wheels with nice mud and snow tires. Old bushings and stock sway bars. No strut bar.
Iv gone offroad plenty of times since. Including mud, snow, dirt roads rain and all. Handles excellent! If I go offroad I adjust dampening to soft to absorb the bumps.

Oh I have a e39 m5 with bilstein pss coilovers without dampening control. I think it's perfect in terms of ride comfort.

I do wish there was someone closer to me that has a e53 and coils on so I can feel the difference.

I'm due for front air bag replacement as my front right seems to sag about an inch over a few nights. My rears are brand new. I'm right at that $ threshold where it'll cost me 600-1000 for refurb or new arnotts or just do bc coils and code out the EHC2. price doesn't seem that much off. I don't mess with my height very much on my x5 so I don't mind the "set it and forget it" If a lowered stance with BC coils ride around the same as stock height airs, I'd consider it.

I didn't have any issues with my factory stuff (as TMV) can testify since he bought the fronts. I replaced it because, despite being a neat feature, I hated the ride quality.

Anyone in the Boston area thats wants a ride in a coiled truck feel free to get in touch with me.

Its so Ironic that you mentioned a E39 M5 with the bilstein pss coilovers as the one you like. This is the one that I liked between the three that I have ridden in. I believe my friend had ordered his set from Turner Motorsports.

i ordered my through tirerack. If there were a set of bilstein pss for the x5 i'd totally jump on it. I've done Ksport coilovers during my highschool years.. thats like +10 yrs ago. those were grueling. I was sick one time and coughed so hard I pulled an ab muscle. The ksports were so rough and bumpy that driving on the freeway was very painful. Are there any forum members with the KW's that would like to chime in?