Boots of Swiftness can be good in certain situations, like against heavy slows (e.g. Ashe, Nasus, Anivia) or if you just need extra map mobility, which is more than likely why it's being used quite a lot on her this time around. But Sorcerer's Shoes are almost always better when you're not in these situations because they directly amplify your burst. I'd say Swifties have niche value, and whilst Sorc's are almost always the optimal choice, there are definitely times where you can pick the others instead, for sure.

I'm glad to know you enjoyed it. 😄