I did use the DSi Browser app back in the late 00s and early 10s, which was indeed worse than the one from any non-New 3DS/2DS model. It takes ages to load a page, and TBT was no exception to that. Heck, even the subpar Internet Browser Channel from the Wii charged pages more quickly than the aforementioned devices.
It's worth noting that the New 3DS/2DS models do feature an improved Internet Browser, which finally allows you to play YouTube videos without the need of the abysmal YouTube 3DS app and make TBT browsing less of an excruciating ordeal. Though, you're still better off using any current gen device for that.
I occasionally browse the internet on my n3ds xl and it works decently from what I have experienced. It makes quite a decent internet browser if you do not have a phone or a computer. Anything else and it's probably asking too much.
Soon... I shall post here from my Wii u but... Later I got the password wrong and now I need to wait!
Edit. I tapped login button without entering my stuff in so my 3ds is also locked!
- - - Post Merge - - -
I bring tidings of great joy from the WII U BROWSER