I, think the regular touchflo is simpler to use because it is exactly that (simple) & boring... a few tabs and thats it. However TouchFlo3D has much more options, looks sweet, touch friendly & interactive; the fact that it takes more time to getting use to or figuring out does not bother me at all.
With this new plugin I rarely see the windows UI and I think that makes a huge difference, at least for me it does.
Another point to consider is how you use the device or what for? I use it primarily for the web, weather, texting & GPS & all of these are extremely easy for me to get to. As far as the extra scrolling to choose a specific city under weather should not be in issue, I set my city & a couple others in no-time when I got my phone and that's it no more scrolling.