Is it reliable to spam wailing stone +1 on hq armor or should I suck it up and stick to +2 stones (assume I'm not going for THE best augments)?
Due to random nature of this system, its almost impossible anyone to come with a definitive answer for this.
First because none know for sure the exact range of +1. Its easier to believe in a limit if you already saw someone with that augment, but how many tries would need to conclude the range is wider? Would need an irreasonable amount of tests, and none ever keep record of that, so basically, none can say the max of +1 is the same of the +2.
From my experience with +1, i would say it really depend. Depend how high is the range of the augment you want. For example, mab or macc. Varying from 0 to 30, its easier to get a decent number with +1. My personal record was 28 mab with +1. Now, for augments with lower range, like crit and da, that vary from 0 to 2, i would say its unlikely to get anything above 1. Ive been trying a some stacks of +1 (maybe 5 or 6) trying for snapshot (goes up to 3), and the max i got was 1, though someone stated he already got 2.
And if you happen to want a mix of pdt and mdt, i would completely say to go with +2. Mdt rate in gear with +1 is very bad. So, if its unlikely having good stats or good pdt and mdt as augments, its even more unlikely to get both at same time.
So, short answer, of you just want average augments, +1 is the way to go. The augments wont be bad. But if you want pdt, mdt and stat, go straight to +2. And if you want to use +2, be prepared to spend a few stacks of that for a single piece. The +1 average is about the same as the +2 average.
Good thing is that next campaign will have increased luck in skirmish, its expected to wailing drops a good amount % in price.