at current price, IRR over life of trust is 11% (assuming remaining distributions meet projections). If they miss by 5% on remaining distributions, IRR drops to just below 10%. So not a bad price at this level, but would like to see below 17 for new shares. In the 16s an awful lot of risk has been wrung out of the stock IMO. All you need to do at that point is either hold till zero, or sell out if it rallies.
In my opinion, reinvesting in trusts does not make sense (unless the price really becomes far too low). You would be reinvesting each quarter in a smaller and smaller future income stream.
Buy early (before the first distribution, if possible), but don't reinvest.
That guideline applies to trusts only, not MLPs since MLPs can add reserves.