I guess its just different companies, so there is always competition but I have ordered from Sarmsx, mainly because a lot of peeps on here vouch for it and have used it with results. Also I personally find a lot more support and information behind them. I think there was actually a Log done on here with a full before and after for about 8 weeks and that was proof enough for me on the Sarmsx product line.
Just my 2 cents