I have two of 'em at present. Both beam models. I never really found a use for them until recently. Nowadays component manufacturers, like Shimano, are getting pretty specific (much to the horror of many) how many inch-pound need be applied to every bolt and it's grandmother. Some have argued, without effect, that the instructions are written by lawyers - and not mechanics. But the logic is pretty impressive and I am one of the mechanics who agrees with them.

I don't see this trend dying out. I see it being specified far more often. I suggest getting the torque-wrench(s). Even if you only use them on rare occasions, you will have a chance to 'feel' different levels/numbers. Learn to feel your way. It seems to rather program it into your memory. I know what, let's say, 60 inch-pounds feels like. So I check my work with a torque-wrench to see if I 'felt' it right. I'm getting quite good - and not just blowing my own horn. So you do program yourself as you gain experience.

Here a neat little hunk of extremely useful freeware to help you learn more:

http://joshmadison.com/article/convert-for-windows