We have a k500s and have been running it for 4 years now. It is a good saw and I will tell you the issues rather than the benefits to keep the post short. The saw has good power and we have never ever stalled it. It will cut 9 feet and I have at times cut 10 foot 3 solid surface quite a few times.
The bearings on the scoring blade are starting to go but I an not sure if this is due to the amount of use or if we had a set of unbalanced scoring blades on for a while. Had a bad sharpening job one time. The riving knife is held in place with an aluminum spacer block bolted to a pressed metal bracket. Thus the knife can get pushed out of alignment with twisting or lateral force. I think that fielder should have made a cast piece or a heavier bracket to hold the riving knife. Not a performance issue, it's just an observation. The outrigger adjusts easily along the sliding table but you have to make sure it is well seated before locking it in place as it will be put of square if not held down firmly. The adjusting bolt for the out rigger squaring is a coarse thread, should be a fine thread to allow more precision. The scoring blade lateral adjustment bolt also has a fast action making it a bit tricky to set the lateral position of the blade before locking it. Once it's set, no problem. We use Mdf to test the alignment. The extension guide on the outrigger is held with 2 hand bolts to the hold downs. If the extension arm is returned to the shortest position aggressively it will actually knock the whole guide towards the blade without you knowing and thus setting the crosscut length shorter. We use a wrench to tighten it down as you can't tighten enough by hand. Just have to treat it gently when going from 8 foot crosscut to compact position.
As for cutting 45 bevel, you have to drop the scoring blade wAy down first as it will rise up a half inch as the saw banks over to 45. In dropping the blade it will go out of alignment so you have to reset it once back to 90. Using the outrigger to cut a mitre works well and is accurate.
Overall the saw has worked very well for us, you just have to keep these things in mind. We are not unhappy with the purchase and After a year we just got used to the quirks. There are some things that fielder could improve on but these issues have been addressed in the 700 series saws and up. For the price the k500 is a good purchase. If we upgrade we would go the the 700 or the format4 series.
If you need more info you can email me