Too Big Of A Jump To Apartments?

[Michael Hooper]

I bought my first house in cash back in 2011. I moved out in 2014 and rented it up until last month, then sold it. The property sold for double what I paid for it, so i'm sitting on about 150K in cash. I'm wanting to continue investing in real estate, but I've really only own one investment property in my life. A friend of mine, who owns a 12 unit apartment complex is wanting me to invest with him in a 40ish unit apartment complex. I've never done apartment complexes before, but he has. I've been doing a lot of research, and it seem like a great idea as long as we wait for the right property. 

So my question is, assuming I trust this friend (which I do), should I pursue this? Is it an ok jump to make, or should I start smaller and work my way up? I do have a full time job, and will slowly build up more to invest, but this would tie up all of my investment capital for a while. Thoughts? 

Thanks