Should I get the rakata alacrity stim? I have the power stim, but havn't found a use for it, as I always use the crit stim when things go pear shaped.
If you mean Adrenals (the short duration, long cooldown Potion-like effects), you should always
be using Power ones. The sheer amount of rating given by these (even after the nerf) is sufficient to push ANY DRing stat so far along the curve that you'll end up getting only very minor benefit from most of it. Power is non-DR'd, and in literally every situation possible, it will provide you with more output.