Cash out refinancing, wait longer for more equity gains?

[Jack B.]

I have on average about 130K in equity sitting in each of my properties, some a little more. Many of them are only 2-3 years old to me (as in I've only had them a few years) and much of the equity is from appreciation. I'm looking at a 70% LTV to cash out refinance and reinvest the proceeds but is it worth it yet?

What I'd get in terms of cash would be:

Property 1: 20K (held 1.5 years so far).

Property 2: 91K (held 6 years so far, paid cash so it's paid off).

Property 3: 48K (held 3.5 years so far).

Property 4: 50K (just bought, would add closets to some rooms and cash out refi 80% LTV.

I have 100K in the bank to invest and save about 70K a year. My method to date has been buying a house about every 1.5 years. It is a bit slow, I'll admit, but seeing returns in real estate I'm thinking of accelerating returns by using the cash out refi to buy more property. If I cash out now I'll have about 300K to invest. 

OR would a HELOC be better in the short term? Would I still need to keep 80% LTV? Or do they loan on all of the equity? Perhaps I'd be better off letting it season for another year...and just use cash on hand now to buy one more house then a couple more next year.