I have thought about getting one myself. How do you like yours? Easy to use? I had a grinder but sold it before using. I can hand file a pretty dam shape chain.
I really like it. I think filed chains have a much better edge than ground if the angles are good. The Stihl bench guide is very easy to adjust and use. Well worth the money IMO, but I don't mind dropping cash on new toys. It's much better than the guides that clamp on the bar. I tried one of those and hated it. I can and do file by hand for quick touch ups as well, but the Stihl unit is great for truing angles/heights back up. It's also fast - maybe not as fast as a grinder, but not too far behind. Once you get the file height and angles set (very easy) you really don't have to watch closely or think about what you are doing. Position the cutter against the adjustable stop, clamp in the driver with the cam lever, lower file/holder, make a few passes, unclamp, repeat. As long as the chain hasn't been badly damaged, I can get around a 25" loop in about 10-15 minutes. Less if I hurry, but I like to watch the file height closely to get the inside top plate angle just right. I really like how securely the cam lever holds the driver. The cutter doesn't move at all when you're filing. Plus, if you have several chains to do, you don't have to mount each one of them on the saw seperately. Handy for me, because I enjoy cutting with really sharp chains and change them often, so I usually have a few to do at one time. I also keep a few loops of square filed full chisel around to play with. To square file, I just take the guide assembly off (just remove one bolt) then use the clamp/rail to securely hold the cutter to hand file. Works great. The unit is made to mount straight to the bench, but it really got in the way when I wasn't using it. So I mounted it to a short piece of 2 x 4 and when it's time to sharpen I just clamp the board in my bench vise. My only complaint is the rail that the chain runs in isn't quite long enough to put the depth gage on and set the raker height without stuff getting in the way. So I just keep an old bar by the bench and set rakers as a seperate operation. The only other problem you'll have is your chains will cut soooo much better than your buddies', they'll be wanting you to sharpen their chains.....