hogs are for ground as what loons are for air
hey, I'm part of the centum family, you might have seen DaRT's videos here and on youtube, have a look at his surgical hog attack, 3 starring max TH9's.
If you use them properly and with some giants or a couple of golums (to take out the AQ) and some WT then hogs can do the job, they're quick and walls are not an issue so they can clean up afterwards as well. just need to scout where the dbl GB are and drop a healing before they enter that area as they don't have a lot of HP.
Hogs can really help you out on certain bases, other bases might be better for other troops. All you need is some practice and then you be the judge whether upgrading hogs are worth it. I have lvl5 myself and their amazing when the base suits that kind of attack.
happy clashing
HD