30 vs 15Y Mortgage & How did they invest before these low rates?

[Rijm D.]

So 30 years is better than 15 since you can pay off the 30 faster if you want too anyways and have a lower payment. Rack up all the good debt weapons now since the rates are at such a historical low, have a lower payment to afford more loans. 

My question is, how did people and investors do it when there were 80/20 loans just before the recession? What were the terms then, 20% at 12%, the 80 at 7% i think it was. How were and had deals to be structured different then they are now, what were the margins for profit and mortgage handled? Interested if someone could talk about that, since these rates now can not stay that low forever, what could we be looking at in the future judging by the past. How did you veterans still make a deal work back then? Knowing that people had invested for centuries even at those high past rates, I wonder how this can be a long term game when rates go back to these 80/20 loans. 

Thanks.