I thought we already answered this....
There's a few differences in the components between an LED tube and an Integrated fixture. They'll both have LED strips running the entire length with a similarly frosted lens. Neither are dimmable, which isn't a big deal. Both have similar warranties.
Pros of Integrated Fixture:
It's tiny.
Pros of LED tubes in a no-ballast fixture:
It's cheaper
You can get more lumens by using LED tubes
It's alot more efficient at around 120-130 lumens per watt
You can replace a tube if it fails.
More choices of CCT (color temp of tubes)
Also, I'd shy away from 8' products. They're too much of a pain to handle and shipping is an issue. Plus, you dont usually gain anything photometrically. Unless you have installation issues, 4' fixtures are much easier and can be spread out to give you more even results.
Good luck,
CD