I wasn't aware of these, thanks for posting them!
Some random thoughts:
UK Supermarket game:
The set is Supermarket Sweep-esque, I really like that. Presentation is easy to grasp--it's multiplayer Grocery Game. It's the most "skill-based" of the two games.
But as a viewer, I'm not sure how I'd be able to play along. I think it may be too skill-based for the average US viewer; Supermarket Sweep works not because the viewer is trying to guess the prices, but because it's so darn fun to watch. The action here is pretty restrained and it only lasts for 15 seconds. It's not as visually satisfying as the Big Wheel.
UK "showcase showdown" game (towards the end of the episode if it doesn't start at it):
Interesting. Seeing all six PG winners sitting at podiums isn't as cool as the Supermarket game or the Big Wheel, but it's still sort of a visual recap of the whole show, and it's neat to see them get whittled down one-by-one in a sort of playoff. It seems like the most "fair" way to eliminate contestants that I've seen so far.
Downsides I can see? Waiting for all 6 people to reveal their guesses takes like 45 seconds, and it's kind of boring. Imagine Match Game if nobody made any jokes.
All in all: I suppose there's a tradeoff. You can get a game that's "skill-based", a game that's "fun to watch", and a game that's "easy to play along with", but the more you focus on one, the more tradeoffs you have to make from the other two.
Supermarket is very skill-based, but "easy to play along with" and "fun to watch" is kind of an afterthought.
The Big Wheel, on the other hand, says "screw skill and play-along factor" and goes all in on being visually satisfying.
The "eliminate the furthest away" game is the closest to the center. It's easy to play along with and it takes a decent amount of skill, and there's
some visual entertainment there, although it's the least memorable of the three.