I'm not really a fan of RM since it is pretty much just osmocote stuffed in pill casings, or at least it used to be, I haven't really checked recently. I know there are claims that it's not the same stuff, but they are eerily similar in form and function. That combined with the overpriced trendy stuff that are on that and other similar sites, the whole thing just turns me off of it. I'm not into buying some magical shrimp powders though.
Either way, a good comprehensive root tab is all you need, just get something that has macros and micros in it and you'll be set. I've used a few different name brand ones and had basically the same results.
If you get the DIY urge you can save quite a bit of money by putting them together yourself, $20 in materials will make you enough root tabs to last until the mayan calendar runs out.