I agree, planes like the Groz do take work to properly tune to cut well, but it can be done. My thinking is they are good beginner planes. You will learn a lot in going through the process, which will still be useful when and if you move up to one of the top of the line planes.
The equation that worked for me was when I was using my plane enough where the constant effort to keep it working (i.e. sharp, flat, adjusted to cut properly) was frustrating - I bought a Lie-Nielsen. The Lie-Nielsen are ready to cut with a minimal effort, and best of all, the stay that way for a long time. I not only use my planes in my own work, but provide them to students in my classes. The time between tune-ups is measured in weeks, not the days between tuning it was taking with the Stanley.
I've traded the extra cost of the great planes for the time it takes to keep them cutting beautifully. And, make no mistake about it, they do cut beautifully. People who use the planes are always amazed at how well/ how different the Lie-Nielsen planes cut.
Are they worth it? Yes, if you're going to use them regularly. On the other hand, if you take the plunge, you'll quickly learn how well they work and find lots of reasons for using your plane. You'll probably also be purchasing more.:icon_thum