Unless you can afford to hold them without producing for some time until everything stabilizes again.

You'll have a hard asset that produces income.  

Then when you are ready to move out, you replace yourself with a renter and now you have a stand-alone investment producing property. 

If your strategy is to create long-term income producing assets, you should definitely sell.If your strategy is to gain as much equity as possible by X date with as much certainty as possible, given the property's track record, you should probably hold until you get to that date.

Does it produce leads?

Putting a property under contract that's zoned R2 (has two rental income-producing properties) and need to do my due my diligence on getting the necessary variances to build 12-15 multi-family units.

Order files extended  and suddenly the sawmills had to start producing more lumber and plywood.

@Tristen M Walker I would start by thinking about the types of investments available to you and what returns they might produce.

Apartments are what a lot of people are trying to get into because of the scalability factor as well as the amount of cashflow an investment group can produce through the asset.

If your first deal goes well, and you're producing great investment returns, then go ahead and use retirement funds.