I have used both. VIdIQ is pretty much useless for tiny YouTubers because you don't generate enough data to take advantage of the large price tag. If your channel is big enough and gets enough view data etc, then it's better than Tube Buddy.
I use Tube Buddy for optimizing my videos, tag suggestions, keyword research etc and for the price, it's great. The nature of my channel means I rely on search for 90% of my views, so it's worth every penny for me. I think video tutorials on both tools are needed (in depth) I am considering creating a Tube Buddy one as it's essentially an SEO tool (which is part o the focus of my channel)
Thanks,
Darren