Good advice. As a newbee, I'll add mine. SDR is effectivly only four months old, since the assets were not transfered until 3/31 of this year. SDT is about six to nine months older (I think) and the promised distributions are similar, but lagging since they started in late 2011. Also, SDR is a little behind SDT in the drilling of its undeveloped wells.
The IPO share price of SDR was (by my calculation) about $19.75; SDT's was $21.00 (I think I read that somewhere.) So, my hope is that SDR's share price will grow as the new wells come on line (just like SDT's has) subject to oil price fluctuations, of course. Also, I expect the distributions to increase over the next five years. After that, my heirs can worry about it. (See my bio.):)