Re: Considering a gut to studs...
considering your location, I would recommend looking at spray foam insulation, it will provide a higher R-value, solid vapor barrier, and superior noise suppression. It does have it's pros and cons, so do your research and make your decision from there. there are also "green" alternatives that are very similar to spray foam that may be more appealing.
A definite advantage to pulling the plaster will be the ability to upgrade electrical and plumbing. Be prepared, this is both a messy and invasive process, know this going in. You're looking at about two weeks if you have pros do the work, not including upgrades. If you do the work yourself, time will depend on your abilities and the amount of help you have with the project.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!