I see a lot of 'thinking' here that is not backed by experience.
Cutting stucco, or old-style plaster & lath is a challenge because it is a mix of masonry (plaster) and steel wire.
The plaster readily becomes dust, flying everywhere and coating everything. The wire tends to grab on saw teeth, transmitting force throughout the wall - leading to the need to repair extensive damage far away from the work site. It's pretty hard to make a patch that won't show in the right light.
Reciprocating saws - Saws-it-alls and saber saws - tend to have their blade teeth catch on the wires. This makes a large part of the wall vibrate back and forth, and cracks appear everywhere.
A circulating saw will work, but the material is death to blades, and dust is thrown everywhere.
Router-type tools, like the RotoZip, work, but dust is an issue, and they're not as controllable as I like. I also have issues with bits breaking, short bit life, and feeling what you're cutting into.
Using an angle grinder avoids the shaking, but the dust problem is still very real. Extensive preparation - tenting, air filtration, vacuuming, lighting, and PPE- is needed. A grinder will cut wood, but you'll smell burning wood.
Frankly, the Fein Multi-Master (and its' clones) stands head and shoulders over the rest. The extremely rapid oscillations of the blade, and the very fine teeth on the blades, make for a controlled, catch-free cut. You can readily feel when you hit different materials. (Since I often find cables right up against the wall, this is important).
I use the moon-shaped carbide grit blade for cutting stucco and plaster. It has no problems with cutting the metal wire. Dust created does not become airborne- it usually sits right on top of the blade as you cut, or falls straight to the floor.
Which brand to buy? I started a very contentious thread over at Fine Homebuliding's "Breaktime" forum, comparing the Fein to the $40 Harbor Freight clone. Look it up here:
http://forums.finehomebuilding.com/.../fein-multimaster-vs-cheap-chinese-clone .
Some guys still do it the old-fashioned way, with chisels, punches, and snips. Unless there's wood to be cut, this way is still often the 'best.' Slow and tedious - but relatively clean and with less chance of damaging the wall around you.
