An underpowered 1x30 will allow you to get started, but it definitely has limitations. I still use mine for some things, but by and large have set it aside.
When I was using my 1x30 at its peak, I used it (and a bench grinder) to profile the blade, files to do the bevels, and hand sanding paper/blocks to clean up the blade. In other words, very little blade work was done on the 1x30. But when I started working on the handles, the 1x30 came back into service.
The problem I had with it is that for me at least the platen on those things isn't useful for bevels. It's too small and the opening around it is too constricting. Invariably, I would end up cutting deep grooves in the bevels because of the awkward way I had to move the blade to do things like cutting in the plunge. The unit is just too enclosed and too much of the sanding surface is inaccessible during operation.
On the plus side, there are a lot of belt types and grits available in that size... but on the down side, they are not all created equal. I found it quite annoying when belts generated a bump at the join, causing the blade to jump every time the join rolled by. I haven't felt this on my new grinder.
So, if that's all you can afford, go ahead. But if you're like me you'll find that it alone is not enough, and then you'll end up spending more on files, other sanders, and so on.
