We have two baby activity gyms at home for reasons I will not bore you with. Here's how they compare:
Bright Starts Start Your Senses Safari Activity Gym
This is the one I registered for and the one Conor had since birth. I think this gym works really well for newborns since the 3 main toys are black and white, yet the mat itself is very colorful. It didn't take long for Conor to love the tiger with blinking lights, he lights up every time it's on. We'd also bring it with us when we're out and about, it'll hang on his car seat handle and him up occupied.
After about 4 months, I noticed Conor was getting bored with this gym. He wasn't as interested in the tiger anymore, he'd grab on the two rattling toys but it didn't take long for him to get bored with them, he wasn't really into teething leaves - it just seems there wasn't a lot of activity he could do with it, which is why I think it's great for newborns but not older babies. We still have it up and he'll still play with it every now and then, but it doesn't keep him occupied for long.
Tiny Love Super Deluxe Lights and Music Gymini Activity Gym
I got this activity gym when Conor was about 3.5 months old and he loved from the get go. There's a lot more dangling plush toys on this one than the Bright Starts one. It kept him very busy whether he was trying to grab them or just suck on them. I'm glad I got this gym after Conor was 3 months old. I don't think he would've enjoyed it as much as a newborn, as he did the Bright Starts gym. We still use this gym everyday and now he's exploring the different textures on the mat itself. He didn't start doing this until about a month ago.