It seems like MoA offers a series of small stat buffs which could be surpassed by crafting your own armor. Then again, with Smithing you can craft a bunch of other useful crap too. Thoughts?
Both in conjunction. If I had to pick just one, I'd got with Smithing, so you can make the thorn rings. Master of Arms is a great skill for a fighter, though.
I'd say it comes down to how much you like making gear vs. finding it. I've found that Smithing is not really satisfying for me to use, especially since you have to put a lot of skillpoints into it to get to the items that you'll use in the endgame. Most skills give you abilities reasonably early on that are useful throughout the game (and most crafting skills are useful throughout without pumping a lot of points in, too). Smithing requires you to get to skill level 4 or 5 to get the same endgame utility. Sure, the potential of dual-thorn rings + Serpentine Plate + etc. is impressive. But so's the potential of maxing out a skill other than Smithing, and I still have the chance to find that gear instead of making it. Though granted the thorn rings are vanishingly rare. That said, I'm not convinced that the benefits of Master of Arms are all that great either. If you want defensive skills, go with Shield Bearer (the turtle proc is impressive), or dual-wielding swords for massive counter chance, or burglary for the invisibility and teleport skills...
Smith for Ring of Iron Thorn. 16 counter and 12 block is huge. The chance of those rings appearing in a normal run is so slim that you might as well call it a strait up bonus. All the other stuff are so common or useless they are not worth the skill points.
Master of Arms is worth it for the piercing defense alone. But I was using it in conjunction with dual wield, so your mileage may vary. As far as leveling skills goes, I always max everything I need, even with smithing.
I'm generally too impatient to grind all my skills up to maximum. I don't think it's ever remotely necessary to win.
I'm rarely as lucky as others seem to be with actually finding good stuff, so I tend to go with smithing, and crafting in general. In my current GR run, I actually went for the Trifecta of Smithing, Alchemy, and Tinkering. I'm on level 6 so far, but things are really starting to get tough.
Vykk: sorry, I misread your "I always max everything I need, even with smithing" as "I always max everything I have", which would imply grinding to maximum level. My mistake. I guess the problem I have with smithing is mostly that maximizing the benefit from it across the entire game requires maxing it early (so you get the most time with all those endgame toys), but I keep wanting to boost other skills that give me active skills, important procs, etc.