Quoting ☮ Phuket:" the floor? i never used those things, well only for my first and she was delayed more so I think because ... [snip!] ... faster when they can move around freely and not be sitting in stuff... id just get a play mat thing to put on the floor"
I think there's some truth to that. My son has always been allowed to crawl/roll around and explore, especially since we don't use a playpen or crib. He was trying to stand at 7.5 months and is trying so hard to walk now (8.5 months). He didn't have much interest sitting in things once he started doing that army crawl thing at 5 months. Once he was REALLY crawling a month or so later, forget about sitting at all. lol We have a jumperoo and exersaucer, like others have mentioned, but he's not in them much. If he's sleepy then he's on the bed with us or in our laps. As for a Bumbo, I don't know how your baby would be with one but Felix never cared much for it. Before he could sit unassisted he'd just slump to the side or try to climb out. Once he was sitting on his own, he just wanted to sit himself. lol