Figuring out who my target group was helped me get the right investors and form long-term partnerships.

We do not represent them.And I can tell you, in almost every case we have an unrepresented buyer on my listing....I make more, the seller makes more....and the buyer is probably paying more than they would need to, and waiving things, or agreeing to contract terms that they have zero idea what they mean or is customary.As an example, almost every unrepresented buyer on my listings ends up paying 100% of the transfer and recordation taxes, when customarily those are split 50%/50% between buyer and seller.

I am a long time San Diego residential RE investor.  

The cadence these days really is still a first-position cash-out.

The worst ones usually don't have any clear cut guidelines (a lot of the underwriters will make up their own rules if they do not like the deal), Suck at communicating (will reply days later), Push aggressive terms to get deals in and then switch them, and Not really motivated to get things done (they will adverse a loan without any hesitation). 

I'm looking to purchase my first official investment property, but I'm running into steep competition against cash buyers. 

This presumes you make smart purchases that cash flow after paying all their expenses (Principle, interest, Taxes, Insurance, and a maintenance / Capex reserves).The risk of leverage is if your properties AREN'T making money - maybe you misjudged your income, or you run into repairs that cost more than you expected or budgeted for.  

Purchase price: $130,000 Cash invested: $20,000 Didn't expect my 2 bedroom rental to rent for what it did.

Have you thought about doing a cash-out refinance instead?

Any mistake can create a domino effect and impact both investments.If your current investment is performing well, save up that money and use it to build a pile of cash for a new investment.