cash out or conventional refi?

[Byron Kim]

Since this would be my first cashout refi, I'm wondering if I'm missing anything here

Property: existing mortgage has 255,000 left on a 30-year fixed at 4.25%, property appraisal estimate 410,000
- current mortgage is $1288/month
- unit rent is $2050 with 1-year lease, market rent is around $2100-2200
- HOA and Taxes push monthly expenses (not factoring other things like vacancy and repairs) to $2000/month

Cash out – can go up to 307,500 loan amount so cashout will be around 51k. Rate will be about 3.5%
- Mortgage payment would be $1381 on a 30 year fixed
- We initially put down 87000 on our current mortgage

No cash out – rate is about 3.25%
- Mortgage payment would be $1110

my thoughts are to take the cashout and take a small loss on the unit until we can raise the rent. 51k would obv be reinvested into the market until we find another property to buy. 

what are your thoughts? It seems pretty straight forward, but since this is my first cash-out refi, am I missing anything here? 

Thanks in advance