As the "standard TV" over here is not much cop - we have our Smart TV linked up to a hard drive and an Apple TV unit.
Although the TV is "Smart" (it's an LG) I never really use the TV based Apps for anything, I just switch to Apple TV and use that. It's a far simpler interface.
The only downside of AppleTV for us is that it does encourage you to keep buying stuff on iTunes..... and I'm weak willed
If I want to watch something on Youtube and I'm sitting on my sofa at home I can:
1. Use the TV remote to fire up the built in Youtube app on the TV
2. Bring up Youtube on my iPad and use "Air thingy" to display it on the TV
3. Turn on Apple TV and use the Youtube App on that
I always end up doing the 3rd option because the TV remote isn't easy to use for searching (you have to point at a screen keyboard and click on the letters... yuck) which means option 1 is a pain, and although option 2 should be simple, the "air" thing can be flaky and drop out from time to time.
With AppleTV I can use the pinwheel on the remote to quickly search and the AppleTV interface keeps suggestions and history which neither the TV App or the iPad online interface do.
I wasn't an early lover of Apple TV, but the more I've used it - the better I've gotten on with it. It's my default now for Netflix and Youtube as well as my iTunes library.