Ah, my apologies for the assumption, it's been almost a year but I'm still too used to Reddit apparently!
Yes, the default launcher had ads, the SHIELD itself didn't, but I also didn't like any of the 3rd party launchers I used but I don't remember specifically why. Then, the SHIELD stopped booting so I didn't want to buy another one and went with the ATV instead.
As I mentioned, I wouldn't necessarily recommend it to someone who knows they'd regret not having the cast functionality, but, if you just want a device that works very well and doesn't ever have so much as a hiccup during navigation, it's been great!
I would still recommend the SHIELD for someone that wants cast or who wouldn't have a problem with (mostly) relevant ads being shown on the device (stock).