Maybe a lot, or maybe nothing.
If you don't know, you can just say "I don't know".
A Tri-Planar U2 costs $6k. A Triangle Art arm to go with my TA table is also $5k (although I'm sure they will offer me a discount because they never sell me anything at retail). But...I can get an Audiomods V with a VTA tower or a Jelco 850 for a fraction of the cost.
Let's say I want to move up from my TA Zeus to an Apollo? Maybe I'll take my bonus and go crazy with a Anna or above? THEN what will a premium tonearm give me?
What "features" matter to anyone? Counterweight adjustment, VTA tower...that's pretty much it right? I can get all useful features out of an Audiomods V, so why do I need anything else? Isn't there a performance difference?