I have owned this Veritas plow plane for some years:
It's a great tool. Like all Veritas products, it is beautifully made with precise machining. There's a skate, a fence on two shafts held in place with collets, a thumbscrew to hold the blade in, another to hold it down and a third to adjust it. On the other side is a depth stop held in place with a final thumbscrew.
It's a great tool but, it does have a few issues. The fence rods fit so tight on mine that it is hard to adjust them accurately, even though they are pristine and lubricated. I view this is a reasonable price to pay for a fence that stays precisely parallel and deal with it by tapping on the end of the rod or on the fence with a small mallet to adjust the fence. You have to cinch the thumbscrews down quite tight or they will loosen from vibration during use and this can damage the groove. Some users complain that the collets don't prevent the fence from slipping but I think this is user error. Tipping the plane out causes the groove to wander inward, putting a lot of force on the fence and causing it to move. Finally, there were problems with the depth stop slipping on early models like mine, but Veritas corrected this with a new stop and it doesn't slip.
My initial results with this plane were awful. The key to using this plane is to keep it precisely vertical all the time and I struggled to do that. I ran into a great rep from Lee Valley at a show, and he told me to put on a secondary fence. I did and it really helped.
It turned out that the main advantage of this fence was that it gave me a good hand position. The key to keeping the plane vertical is to use your rear hand to push forward ONLY and your side hand to push in ONLY. For me, the handle is wrong because it is above the fence. If I just push on it with my palm, I have a tendency to tip the plane over. Of course, my giant paws don't help. The auxiliary fence solves this problem for me:
Narrow and/or thin stock presents challenges, so I came up with a jig that I am quite happy with:
By lining the workpiece up precisely with the 1" side of the jig, I am able to keep the plane vertical on thin stock. For thicker pieces of stock this isn't necessary and standard workholding methods are fine.
I encountered a final issue when working with white oak. If you are plowing against the grain of the wood, it can tear out along the edge of the groove quite badly. The best solution, of course, is to buy a left and right hand pair of these planes, but at $285 apiece that's a little spendy. Taking very thin shavings at first and using a mortise gauge to sever the fibers on the surface are two ways to address this.
It has always been possible to make narrow rabbets with it but now wider blades are available. They also now make tongue cutting blades and beading blades in different sizes. I expect to be trying them in the future.