User blog comment:TheTobarMethod/So...Tri-Force Vayne lol?/@comment-5839977-20130304003653

Vayne is quite strong lategame, partly due to her reliable, hardhitting Tumble and her True Damage on Maximum Health Proccs. She also has potential Hard CC (unusual for ADC, usually soft CC at best, exception is Ashe, hurr durr) and an Ult providing her with a neat self buff. Damage, mobility and stealth for the fun of it. She is among the best 1v1 champs in the game, and the fact that tumble affect lifesteal makes her surprisingly resilent.

The reason I find Triforce lackluster on Vayne is simply because she only benefits from some of the stats. Mana is usually not that big of a problem on ADC's anyways, the Ability Power is a complete waste except if you build Deathfire or Lich Bane or something... Which no sane person would do on Vayne. The Icy (slow) has reduced effect from ranged, and Vayne already has a very effective chasing tool from her passive (although it can be very good for having time to reposition for a condemn) and the Spellblade, with its maximum 160 bonus damage (Yes, Vayne only has 108 base AD lvl 18) falls off when considering it can't crit and has more Cooldown than Tumble (Realistically. The Spellblade proccs upon cast. The cooldown of 2 seconds starts upon autoattack. Tumble has 2 sec cooldown BASE at rank 5, without CDR, starting on cast. So either you miss half of your proccs or you aren't effectivly using tumble's damage component/autoattack reset.)

Skimping out on survivability for Trinity Force isn't worth it, I'd say. Zephyr provides better movespeed, Tenacity, more attack speed, almost the same AD, and CDR. Black Cleaver gives you the same health, armor reduction and CDR. LW gives you armor pen. Also, building Trinity Force kind of dedicates you to it. Once you start building Sheen or Phage, you better finish the entire item, or you will delay your build A LOT. Gives you less flexibility. All in all, it's a good item, don't know if it's worht the gold and effort in a real game though.