My newborn absolutely loves his bouncer. He uses it every day! When he's ready to play, he'll hit the giraffe and lion. When he's ready to nap, I put the animal bar away and he is relaxed with the vibration and song settings. The battery life seems pretty good as well. My son is almost 3 months old and we've not replaced them yet. The vibration and song switches do switch off after a set time. The vibration stays on longer than the songs, so normally long enough for my little boy to fall asleep. Sometimes I forget to switch it back off, and it hasn't seemed to make a difference. I started out strapping him in, but I think it's only really necessary when he's a bit older.
Putting it together was pretty straightforward, though the instructions could be a bit better. My husband had to push part of the base in for me because it was a little off and I wasn't strong enough. Might have just been mine.
All in all, I think it's a great toy for newborns. It wasn't as expensive as a lot of bouncers and it definitely has been great for both activity time and nap time! My son has a reflux issue as well and it supports his head nicely so he is comfortable.