Hi Gretchen.....I hope you find a home that you will be happy in. First of all though, try not to fall in love with a building. They can't love you back. I have a deep appreciation for well-built structures but love should be a reciprocal affair.
I've inspected dozens of older condominiums in that stretch of LSD. As Ken stated, the old galvanized pipes slowly constrict from rust and minerals. The only permanent repair is to replace them with copper pipes. Some buildings have done that and should be relatively trouble free now. Look around, take your time, there is a lot of property on the market. Like the good book says, "Be anxious in no things".

Take a close look at the minutes of the association meetings going back over the previous year. What type of issues have come up? How has the association responded to complaints? What type of repairs are being contemplated? How much reserve funding is on hand? Is it hard to get enough hot water at 7:00 am when everyone is in the shower? How often do the maintenance staff need to unclog, blow-out, or rod the water supplies and drains?

Get to know the building and maybe, just maybe it will prove itself to be worthy of your affections!

I don't know the answer for everywhere, but I live in a vintage building on LSD and don't have any smell problem with the plumbing. Very occasional, very mild rust in water. Water pressure is fine.

Unless the sewage pipes themselves are leaking, it seems unlikely that the toilets would smell, since the waste sits below/behind the bend in the pipe and the water in the bowl.

So I think the answer is to spend some time in inspection devoted to the plumbing. But it's not a universal problem.

Gretchen, Gretchen, Gretchen! Hire a Licensed 130 Union Plumber Only ! To help you with this matter. Call 800-76-VALVE and ask for one in your area. I will never ever use anyone but a 130 Local Union Plumber .
They have helped me with a number of old projects.

Gretchen,

Older buildings can have issues with their pipes. Cast iron risers bring water up throughout the building which can corrode from the inside resulting in a build-up of rust and grime at certain locations causing a narrowing of the pipes that deliver the water. The only solution is to open walls and replace the risers throughout the building which is a massive undertaking (individual sections can also be replaced but that can be a short term solution and difficult to locate the offending section of pipe).
Having toilets that smell would seem to indicate a problem with waste build-up due to blockages in the building waste stacks or sewer lines again due to corrosion. It's difficult to check for these problems as they are behind the walls but the tell-tale signs of issues are what you describe.

Hire an inspector knowledgeable in older buildings, review the minute meetings and ask the management company for information on past and future maintenance. At that point you'll have a better understanding of what you're getting into and can make an educated decision about buying or moving on to the next building.
Bets of luck, Ken.