The last Fine Woodworking/Homebuilding tools review had reviews of jack planes and their review agreed with @Huxleywood
's on the quality of the Wood River plane - just took too much fiddling to get it tuned up correctly, and the fit and finish wasn't as good.
I've used several planes that were not LN or LV, and they were not quite right out of the box. In most case the sole was not flat enough to do quality work, and in some cases the blade as well. My experience was that I could tune those two defects up, but it took a couple of hours of time (using float glass/granite and sandpaper), and the results were not as good as getting a plane that is properly tuned up out of the box. In some cases, the mouth suffered from the tuning, making it hard to adjust properly. If the sides are not square to the sole, that is really tough to fix - the one time I tried, I failed - but that is not as important unless you are using the plane to shoot.
For my money, LN and LV are worth it because they are properly tuned out of the box. I have 17 LN and LV planes and I've never had to do more out of the box than smooth the backs of the blades behind the edge and hone them. If the soles and blades are not dead flat out of the box, or if the sides are not square to the soles, you send them back. Furthermore, the adjustments on both brands work well - the worst problem I've had with either is a little slop in the depth adjustments, and even that was an exception, and minimal. I started out buying LN because I got a really great deal from a co-worker who was giving up on woodworking. Now I tend toward LV because of the PMV-11 blades, which live up to the hype, especially at a slightly steeper honing angle - say 30 degrees rather than 25. For both LN and LV, the bodies are made using material and manufacturing techniques that should keep them stable, so that everything stays flat and square over time. I've not had any problems with my LN or LV planes, some of which have >20 years on them.
BTW, of the LN planes that I got second hand, the only ones that I haven't used on a project are the side rabbet planes, and a beading tool. Of the LV planes, the only ones I haven't used are two skew rabbeting block planes and a plough plane, because they are new and I just got them ready to go yesterday. The two block planes were easy - hone the blades and adjust the depth and lateral positioning. Honestly, the plough plane seems really finicky, and I think I'm going to need to add an auxiliary fence to get the fence bearing surface that I need to make good cuts. Or refine my technique - this is the first time I've used one.