Scenario 1 - Roll over in 401k or leave in existing 401k (either way I do not pay fees according to both companies)401k Balance $49,822Link: http://www.bankrate.com/calculators/retirement/401...Assumptions Annual Rate of Return - 8.05% - this is the annualized rate of return since initial purchase Current Age 33 Retirement Age 65New Annual Salary $112,500Percent to contribute - 10% Retirement Balance (before Taxes)$3,947,497 with rollover$3,354,007 without roll-overDelta $3,947,497 - $3,354,007 = $593,490.00 I believe this is the number to compare against.Scenario 2 - Withdrawal and pay 20% tax and 10% penalty on 2017 return and invest in rental propertyLink: http://www.calculator.net/rental-property-calculat...Current 30 year FHA mortgage @ 4.75% with PMI.

A large portion of my background involved investment analysis.unfortunately, although my homework was correct the underlying assumptions were not.

Your strategy can work1 you assumption is wrong a bigger house will not rent slowly   As for how fast it will rent, that is a local sub-market question that I cant answer. 

Please note that my assumptions are estimates from my own research…if they are off, maybe more experienced investors will be willing to comment and correct me.1-Finding the DealSFH - might be easier to find, can buy in multiple markets.MF - very hard to find good deals…investors with deep pockets are looking into MF also2-Financing the DealSFH - to get a good deal one might need cash upfront and cash out refi/leverage later after rehab and renting…conventional financing is possible, but it is limited to ten properties...after ten SFH’s, portfolio lenders are needed in order to scale-up...somehow easier to get discounted properties and follow the BRRRR methodMF -possible to finance with the right down payment, good credit score, documented net worth, MF proven high occupancy rate & financial records...because of higher costs, it might be difficult to purchase a MF at a significant discount and rehab it...BRRRR strategy hard to reach3-Cash FlowSFH – might be able to cash-flow $200/$300 per door/month in some markets after OPEX/CAPEX and loan servicingMFH – most likely $100 per door/month after OPEX/CAPEX and loan servicing4-ScalingSFH – hard work, many transactions with different rehab issues...a well oiled system and a good team are neededMF - definitely easier and faster to scale up.5-CAPEXSFH – more costly to maintain since there are individual properties.

@John Carbone First, you are making a false assumption regarding STVRs.

The tax payer will remain Sub LLC as we plan to do a debt assumption agreement post closing, where Sub LLC will assume the debt for the property.

I have been underwriting many deals in my market and have encountered a deal requiring loan assumption on a 20-unit apartment.I have many questions to ask, but I want to understand from here before meeting the owner's bank and outgoing owner.Q1. what are some of the fees besides assumption and processing fees to anticipate?

However, keep in mind that  agency debt is often "assumable", so you may be able to simply transfer the loan to the next buyer, without paying the pre-payment penalty (although there is going to be some assumption fees for the transfer.)Another consideration is that if you're going through Fannie Mae, there's something called a "supplemental loan" which can help you, or the next buyer, to re-leverage the property if the equity has increased a significant amount.Hope that helps!

I'm replying to your question with the assumption that you want to be a passive investor. 

This is what I'm looking for, but rather than a mentor I'd like someone on the same level as me so we can bounce ideas off each other, check each other's work/assumptions.