Glacius UV useless?

So I got a Glacius and I put 2 random UVs on it, Slime bonus damage medium and attack speed increased high.
I tested with a friend the difference so is he trolling me or does ASI high nearly don't do shit?

ASI definitely speeds up your attacks. It is quite useful both offensively and defensively. To learn about it in general, read Abilities. To see how it affects Glacius in particular, read this combos/minute data set.

I love getting ASI on my brandishes. However it doesn't suddenly turn you into a tornado of stabby stabs. It's subtle but noticeable.
There's a reason why most people don't worry bout UVs until late game.

Each level of ASI is roughly 4% so no, it isn't going to feel like your sword is one thousand times better but what it is going to do is shave off 1/10th of the time it takes you to attack. Consider that this ability stacks with damage in the best possible way- at +6 to each you have 1.2ish * 1.24 = 1.5ish. That is to say that you're a good 1/4 closer than you would be to having a 1.5x DPS multiplier in place.
first off, might want to edit out the swearing, GMs reading this won't like that.
ASI is still useful on brandish weapons. Maybe not if you are used to only using the charge, but it's useful if you use the regular attacks
Also if your friend is using swiftstrike buckler he will also have ASI high so there won't be a difference.
Try it with a swiftstrike buckler yourself, you'll have ASI max and that should be noticable.