I've had the FWB P85 for several weeks now, and made some direct comparisons with the Steyr LP50. The trigger on the P85 is slightly better than the LP50 trigger and has more options for adjustment. On the other hand, it is possible to remove the trigger unit on the LP50, and if you have several trigger units you can switch from e.g. a 500 g. trigger to a 1000 g. trigger in a few seconds. Both pistols have a pressure point trigger, but due to the semi-auto mechanism there is a tiny bit of creep after the pressure point on both, so let's say they have a very short roll type trigger. The P85 trigger has a little shorter "roll", and it feels a little smoother, than the LP50. But the difference is not greater than that you don't necessarily notice it if you don't have the opportunity to shoot with both back to back, or have shot both pistols for a long time and know them well. For rapid shooting this trigger characteristic is not as critical as for precision shooting. And both pistols are made for rapid shooting rather than precision target shooting, so I think both pistols have good triggers for what they are made for.
The grips on both are good. They can be tilted, adjusted back and forth, up and down, and turned a little sideways. On the P85 you can do this without removing the grip, while on the LP50 the grip must be removed to make these adjustments. The grip on the P85 can be adjusted to a shorter reach than the LP50. Something to consider for people with small hands and/or short fingers.
The sights on both the P85 and the LP50 are top notch, they are the same as on the P8X and the LP10 (but not the EVO10). On both, the width of the rear sight notch can be adjusted. The adjustment screws for up/down and sideways can be easily operated with your fingers, no screwdriver needed for these adjustments. The front sight can be replaced to other widths on both guns. The sights can be tilted around the longitudinal axis on the P85, but this is not possible on the LP50.
A significant difference between them is that it is easier to attach a red dot sight on the LP50. Steyr has its own Weaver mount that slides onto the barrel shroud, and it is also possible to mount a short Weaver rail where the rear sight is mounted. On the P85 there are no such options. At least not yet. The rear sight on the P85 sits on a dovetail rail, but this is a little wider than the standardized dovetail, so a standard dovetail mount doesn't fit very well. And a mount might also get in the way of the cocking lever. The only easy option is to remove the barrel shroud and put a clamping mount on barrel (the barrel measures ø12mm). It is possible to mount a Weaver rail where the rear sight sits, but so far that is a custom job that must be precisely machined to avoid slack. I have a couple of designs on CAD, but they require too much handling and are not very production-friendly so far.
Another difference is that it is much easier to mount a silencer on the LP50. On the LP50, the compensator can be removed and an adapter with 1/2" threads can be inserted. This is not possible on the P85 as the compensator is integrated into the front sight housing.
In terms of air consumption, the FWB manual says 140 shots/fill. I get +150 shots out of my P85 before I must refill. The Steyr manual says 120 shots per fill, and that is about right. Both delivers as specified and expected.
In terms of muzzle velocity, the P85 manual says 145-155 m/s and mine shots the RWS Meisterkuglen 0,53g at 146 m/s, average of 20 shots. The LP50 manual says 150 m/s and mine shoots an average of 144 m/s with the same pellet. My experience is that most brands are a little optimistic regarding muzzle velocity, so I will say both pistols deliver as expected.
Regarding weight, the P85 manual says the P85 weights 980 grams, and the LP50 manual says the LP50 weights 1050 grams. I haven't checked the weight of my pistols, but I think we can trust the stated specifications. Anyway, there will always be a little +/- depending on the wood in the grip. Both pistols allow you to place the included barrel weights on the side of the barrel shroud.
Both pistols are very good. The P85 feels a little more contemporary and up to date in some areas, but I have no qualms about recommending eighter of them, depending on the use. The LP50 is a well proven design, it's not pellet picky, and it usually just works. Time will tell if the P85 will be just as reliable, but it looks promising. I've put around a thousand pellets through mine now, and no hick-ups so far.
FWB P85 -> A slight edge for ISSF 10m rapid fire shooting. A little better trigger, with few more options for trigger adjustments. ~25 more shots from a full cylinder. Possibility to tilt the sights on the longitudinal axis. No options for accessories at this time.
Steyr LP50 -> A well proven and very reliable design. Available options for accessories (optic sights, silencer etc.). A little cheaper and still a very good alternative for ISSF 10m rapid fire shooting.