Generally you’ll see two forms of jig saws: barrel grips and top-handle. Milwaukee clearly took a third path with their M12 12V saws, and at least on the surface it looks like a pretty slick idea, incorporating the heavy grip benefits of top-handle with the fine control you get from barrel grips.
It looks to me like you’d hold one of these pretty much the same way you’d hold a barrel grip — one hand around the barrel and the other on top, steering the thing and stabilizing it as necessary. Except in this case, instead of sort of randomly grasping the barrel, you actually get a fully shaped grip. You also get a variable-speed trigger instead of a switch and a knob.
Of course, if you’re doing a lot of cutting that might not work out so well. There’s something really nice about dialing in the speed and just letting it run for longer cuts. Here you’ll have to hold the trigger down, which could wear out your finger over time. Then again, you can easily slow down a little if you hit a rough spot with the Milwaukee. That’s pretty awkward with the dial-type models.
Besides the unique form, the specs for the M12 (Model 2445) look pretty much as expected: 0-2,800 SPM and a 3/4″ stroke. One can suspect a very short runtime with such a small battery, even in the days of li-ion technology, which might render this “wear your finger out on the trigger” issue moot. Really, this strikes me as a small-project or quick-finish saw, which, in my opinion at least, makes a lot of sense.
Street pricing for these runs about $150 in kit form, consisting of the saw, battery, and charger. If you plan on doing more than even a little cutting, you’ll need additional batteries — pretty pricey at around $36 each. If you’ve already got some M12 gear, you can score the bare tool starting at $120. (Sadly, no great savings there.)