GRM and cap rate both looked great, but when we pulled utility records, we found heating costs in winter were brutal because of old, inefficient systems.

I'm glad I said I had to talk it over with my financial advisors. :) 

Record keeping and providing evidence are the key.Airbnb: toilet is reported as clogged on 4th day of 5 night (6 day) guest stay.  

--------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

As someone new to NYC, I'd appreciate insights on:The current state of the UES market in this price rangeWhether buying makes financial sense for a 3-year timeline versus rentingThe pros and cons of co-ops versus condos in the neighborhoodI'm particularly interested in hearing from those with experience in the area, as I'm looking to make an informed decision.

I leave the marginal ones waiting, letting them know I will reach out when I have a showing date/time.At the showing, I collect their completed application (sent via PDF prior or filled out on premises), scan their photo ID and last 2 pay stubs.Then, I do some digging around online (social media, court records, Google) and if it looks like they are representing themselves to me accurately, I contact them and send them a link to do the background checks (paid by them directly to the vendor). 

Was everything ok at the end or did it end you financially?

If they are separate, permits would have been pulled and the city will have records of those permits.  

If you are looking at nationwide, maybe narrow it down to 5 or so markets that interest you and look good financially. 

They focused on renovations that appeal universally.. think updated kitchens and bathrooms - and kept meticulous records of their expenses.