Having used come-a-longs and hi-lifts as come-a-longs, I would never wish that agony on anyone else. It's better than nothing, but far worse than an electric winch by a long shot.

Generally speaking, if the engine can't start/run, and help is nowhere to be found, winching the vehicle out will be more trouble than its worth. The best part of an electric winch is you may use it in conjunction with the engine when solo, meaning you can generally free the vehicle as soon as you find some traction, rather than constantly advancing, re-entering the vehicle and checking for traction again.

But you're right about and additional strap: one should always have with their winch, at a minimum, a tow strap and a tree saver (plus requisite shackles, snatch blocks, and gloves if using wire rope, or rock guards with synthetic). I once got stuck deep in a ravine, and 150' of synthetic rope fell short of the nearest tree by 5 feet, but a tow strap and tree saver made up the difference and I got to sleep in my bed that night, rather than in the jeep.

I've owned an 8000lb come-along in the past. Pulling my truck from the mud, the cable came off the pulley. I replaced it with a new come-along from a different brand, and again the cable hopped the pulley. This damages the pulley and bends the axle, rendering the winch useless. They're less than ideal for vehicle retrieval, especially if doing intense labor is not a great idea (like when you're at risk of hypothermia). Pulling a stuck car with a come-along is a very laborious and time-consuming task.

There are wheel-mounted winch pullers that are much better suited for the task, since they don't require standing out in the cold or as much physical effort.

http://www.bushwinch.com.au/recoverysystem.html

That looks really cool, but $1000 for it is insane! It's a small metal drum and some cable.