I'm putting this up because a lot of people ask this question, including me. The conclusion I've come to is that a good jigsaw is better than a bad bandsaw. I want to make comparison between four tools I've used recently that span a wide variety of quality. I realize there's much more to say on this topic, and I don't intend to do any comprehensive reviews. I just want to make a simple point.
I want to look at four products I've used:
1.) Grizzly 14" Extreme Series Bandsaw ($625)
This is by far the best of the four. I don't own this saw. A friend of mine (jmrentis) has it, and I go to his house when I have to do bandsaw work. Really, I think this is the ideal tool for hobby guitar work. I know there are better saws out there, but this really does everything you need. However, you're going to shuck out a bit of money to get one, and it needs floor space.
2.) Ryobi 9" Bandsaw Model BS903 ($100)
I picked one of these up at Home Depot about six months ago. I didn't keep it long before I returned it. I don't want to be totally unfair to this tool. Maybe others have had success with it. The 9" reach makes it really tough to cut into the horns. Plus, it felt like it was working to cut through an 8/4 body. It's a benchtop model, so it can be stored when you don't need it, but it's heavy.
3.) Bosch 1590ESVK Jigsaw ($150)
I got this saw for Christmas. It's amazing. The big problem with jigsaws is that the blade drifts, because there's nothing to hold it at the bottom. It will drift a little, so you need to give yourself some distance from the edge if you're rough cutting a body (1/4"?). Before I got it, I remember someone telling me it cuts through wood like butter. I can attest to that. After making sharp turns on 8/4 walnut all day long, I have to say that I'm kind of blown away at how good this saw is. It won't touch my friend's Grizzly bandsaw, but it blows away the Ryobi. At least I think so. And it fits in a drawer, which is important to me. (Ok, it's important to my wife.)
4.) Old Black & Decker Piece of Junk Jigsaw ($30 a long time ago)
This is the jigsaw that made me hate jigsaws. I'll say this for it. It makes a jigsaw blade go up and down....unless you're trying to cut through 8/4 walnut, which is a task it does not like to perform. It didn't have enough power, and I wouldn't consider taking it near something I really cared about. The jigsaw is as good as new - I've hardly ever used it. I got it new about ten years ago. So it's not broken. It's just a piece of junk.
So these are four extremely different tools. I list them here for the new builder, in the hope that someone might gain some understanding about what sort of saw will best suit them. Can you build a guitar with a jigsaw? Yes. Is a bandsaw better? Yes, generally speaking. I am of the opinion that if you're limited in funds and work space, you may be better off with a jigsaw than a bandsaw. I know westhemann swears by his Delta 9" bandsaw, and different things work for different people. I also know you don't have to spend $150 to get a good jigsaw, but you probably shouldn't get the cheapest one you can find. I can't recommend the Bosch 1590 enough. Thanks to everyone who encouraged me to get it. But I know it's not the only good jigsaw on the market. I do feel confident in saying one thing. Lousy jigsaws and lousy bandsaws are not appropriate for guitar work.
Hope that's helpful.
-Dave