Are there any benefits I may not be aware of here? 

Also, the benefits of a cost segregation study can vary based on a multitude of factors.

For long term, the main benefit is having someone else pay off the mortgage on an asset while you collect cash flow.

Rentals generate passive income, so an S-Corp offers no added tax benefit.

Purchase price: $20,000 Cash invested: $45,000 Sale price: $99,000 Contributors: Peter Vekselman Partner Driven and Amanda Frecks teamed up for an exciting flip on Main St, Grainfield, KS.

There are a number of tax strategies which you could benefit from.

I mainly want to ask if these assumptions are reasonable and if there's anything I haven't considered:(1) multifamily units in NJ close to New York City, ~$1,000,000, 20% down payment, (2) Using the following assumptions: 4% appreciation rate, 6.5% interest rate and 5.0% refinance after 5 years, $10,000 yearly maintenance fee(3) ~$6,000 monthly rental and assume 3% increase yearly with 5% vacancy rate(4) Based on the above, the calculated IRR if selling at the 10th year is ~19% (considering tax benefits) and ~17% (without tax benefits).

It just adds complexities and costs without any benefits. 

Quote from @Dean Sexton: There are benefits to both options.

Main benefits to this strategy include:- Low down payment options (as low as 3-5%)- Acquisition experience- Property management experienceThe NYC metro area has nearly 2,000 available 2-4 unit listings on the market.Other new investors consider the BRRRR Strategy.All the best to you on your journey!