I used a TVLB loan last year to buy the plot I built my house on. It is pretty straight forward and you will do everything on line, in fact I don't ever remember speaking with anyone. Couple of points.
$150k is not much. I actually needed $165, and put 15 down of my own money. Unlike the VA, this is an actual loan, not a guarantee like a VA loan. TVLB is loaning you the money like a conventional bank. If you do not specify, that you want the whole $150k, they will take out a 10% down payment.
The interest rate is a bit higher than some banks, but not by much. Again this is a loan. I had to submit all my docs to them, just as I would a loan. I probably could have obtained a conventional at a better price, but there is no points and I just needed the money for a few months. But quite honestly, they needed just as much documentation as any bank would. That said, I think they will underwrite some riskier loans, because of the veterans aspect.
Depending on how much you want to borrow, this may or not be the option for you. A lot of good advice on the ag exemptions, etc in the previous posts. My thoughts are that the TVLB has become somewhat outdated due to the increase in land prices. Not much you are going to get for $150k. But if it is your only option due to credit or other circumstances, may be for you. PM me if you need any more detail.