Pros:
Cheap, rent stabilized. An adventure. If you're good with legal matters you might be able to make a lot of money suing them.
Cons:
Extremely bad management, maintenance, and condition.
They do extremely superficial maintenance between tenants to get people in there, but it's like they're just plastering over leaks and such. Radiators leak, the roof leaks, plumbing leaks, electricity is unreliable/wet. Multiple tenants have sued. Multiple units had ceilings collapse while I lived there, including in newly "renovated" ones. Toilets leaked. The place is falling apart and isn't safe, it should probably be condemned. I won't be surprised if an electrical fire or gas leak leads to it burning down. They'd probably love for it to be condemned, they've tried to buy-out some of the long-term rent stabilized tenants.
Once you're in there they don't really fix the stuff, but you'll have random unlicensed contractors and handymen in and out constantly to check on things or tweak the fundamentally unsuitable systems to barely keep things going. They can leave water dripping through your apartment for weeks. If they knock a hole in the wall to look for a gas leak or check an electrical wire, they're not going to patch the wall until you move out, and so much is broken they can leave it looking like Swiss cheese. I got mildly electrocuted plenty of times living there and the fire department had to visit too.
Once they suddenly decided to redo the staircase to try to get new tenants. It looks OK now, but during this construction project they left piles of construction rubble on the stairs, nails sticking up, dirt everywhere for weeks. They wouldn't sweep the stairs at the end of a day of work, or even move the construction supplies so we could get up and down the barely-present being-rebuilt stairs.
When maintenance people do show up it's hard to know if you should let them in, since they may just do a bunch of random damage, or there may be a legitimate emergency. They've entered units many times without permission and some tenants changed their locks.
They won't pay for furniture or clothes that will inevitably get destroyed from water and drywall dust, and will still eat your security deposit when you leave. Don't trust their online payment system either, call your bank to preemptively stop-payments in advance when you move out. Assume bad intentions or incompetence in every interaction.
They keep changing the name of the management company to try to hide bad reviews online. The specific issues changed but issues were pretty steady, and there are older reviews. If someone says they're a new owner or new management company of this building, I wouldn't believe them. The building changed hands while I was there and I think it was father to son or something, it seems to be a family business.
Also covid didn't really make a difference and most of our issues were pre covid, but when covid did come the landlord never wore a mask.
Advice to owner:
Stop being a slumlord.