It's not horrible or anything, but I have a few issues with it:
1. Your damage is pretty low at that SL. Against heavier armor enemies running things like giants the *only* things you'll be able to do are fish or hit + roll, but you'll have to hit + roll a lot because each hit won't do much.
2. All greatswords, hammers, UGS, axes (other than hand axe), great hammers can stagger you in 1 hit. UGS and UGH are probably too slow to staggerstab, but the others aren't, and a number of these can stunlock you. Conversely, you'll need 2 hits to stagger even fairly low poise builds, but anything over 60 and you'll need 3 even if you 2 hand.
Basically, you're running a hit + run build that has OK but not amazing range without any boosts for the pyros and no way of materially buffing your weapon. Think about, say, a fast rolling build with 60+ poise and a claymore:
http://mmdks.com/371k
Now note that this is even a slightly lower level...but the build can stagger you for multiple hits off any 2h claymore attack, any black flame (if he goes 125 with 45 dex BF can stunlock you!), and even if you swat him twice all he has to do is hit you once and you lose the trade, despite slightly higher defense for you.
What about fastroll dragonslayer spear builds? I don't see how you can pressure them. Even opposing katana builds might be very hard to deal with, such as this:
http://mmdks.com/371q
You'll see stuff like that a lot :p. Not only does their primary hurt more than yours, but it does so PRE-buff. With the buff on it's absurd. I threw on the "try-hard" mother mask for comparable HP, still having more poise, so this build does more dps AND still wins the poise race. Now you attack at the same speed, but you absolutely can never do anything aside from attempting parries/fishing or beating them on spacing/avoiding trades. You lose 1:1 trades, can't even attempt a 2nd hit, and they have all the confidence in the world to run up and kick you, r1 spam, etc because they know they can take 2 hits off you even if you 2h your weapon, and you can't take 2 2h hits from them, and kats hit FAST!
The only build you have some advantages over are tanks, but you have to hit them and escape without a return hit otherwise you're probably getting staggered + taking more damage.
Builds have to be designed carefully. If you carry some spare weapons you can make your matchups more favorable, but in all honesty there should be 1-2 things your build is either the best at or right up there with it. For katanas that's mostly fast dps or pokes/rolls, but you don't have the poise to threaten fast dps nor the damage for the pokes to be overly threatening to most of the standard SL 120 buff builds, hornet fishers, etc.
Plus I think Endurance dumps are better then Vitality dumps, even though the two kind of go hand-in-hand
This is objectively true. After family mask nerf you always get more efficient stat usage by going mask of mother + endurance as opposed to mask of father + vitality. In a true min/maxed build, there should no longer be such a thing as a giantdad, they should all be moms unless you need the equip weight at 99 end.