I think it all depends on the individual sitch.

Some have said the physical separation was key to reconciling...others the in-house worked.

Since I have been the recipient of an in-house mlc'er, my thoughts:

-The Bad Aspects
--You get to watch the craziness, mood swings, OP play and be available for the abuse attempts.
--You always have to be "on show" and in control of yourself, few breaks from the craziness and abuse attempts.
--The temptation to snoop..."Oh look, the cell phone and computer are just right there"....
--The kids get to watch. And they do.
--Few times to be alone and mourn, rage, breakdown, throw things.
--Tempting to get expectations up when there is a day (hour, minute) of clarity and niceness in the mlc'er.
--You get to pick-up all the slack with the mlc'er abandonment.

-The Good Aspects
--Assuming your changes are for YOU first and foremost, you get to demonstrate your changes and that you are the better choice. Daily.
--The kids get to watch. And they do.
--The family is still intact, somewhat.
--Finances don't take as big of a hit.
--You get to REALLY learn what you are made of.
--You get to take the mlc'ers "temperature" (this can be bad as well).
--You really get to learn what you can, and cannot, control.
--If you have a great sense of humor, you are in a rich environment.
--If you have any inclination towards anthropology...you get to wear your "double secret closet" Jane Goodall hat and safari outfit.

There are more plusses and minuses, that's all I could come up with off the top of my head right now from my sitch.

That said, W threatened moving out, a lot, until I called her on it and said, "Okay, then leave" (and meant it and was sure I could follow through). Haven't heard it since as a threat attempt (and it also started a change in her dynamics, they are such bullies). I also was at a point to kick her out about this same time period...so...your mileage may vary.

Taking increasing the chances of R out of the picture, what do YOU think is best for YOU and S?

T^2

In the depths of winter, I finally learned that within me there lay an invincible summer. - Albert Camus

Uncertainty is the very condition which impels people to unfold their powers.-Eric Fromm