I completely agree with everyone else who said it's not the "bucket" or the stroller itself, it's all in how you use it. I used the bucket carseat with dd until she was about 6 months and outgrew it (check your instruction manual, b/c they all say up to 20 pounds but there's also a height limit of 26 inches, which most babies exceed before they reach 20 pounds!). I only used it for three things - as a carseat, obviously, in a stroller (I had the kind that you could attach the carseat to), and to bring her in the house if she was asleep. I was shocked to see people who just left wide awake babies in it for extended periods of time. If dd was awake when we came into the house, I took her out immediately. When I used it in the stroller she was facing me and I was always talking to her - I actually used to run into walls sometimes b/c I wasn't looking where I was going!
And when she outgrew it and rode in the stroller facing outwards, I still talked to her all the time, even though I couldn't see her as well. People used to look at me funny because I guess they thought I was talking to myself - amazing that it wouldn't occur to them that I was talking to my baby! I have also noticed that a lot of stroller-bound mall-babies seem to have a glazed look about them, but it's not the stroller, it's the fact that their moms ignore them and just push them around like they are PART of the stroller. I also don't understand how many of dd's age-mates (She'll be three next week) still sit in strollers when out and about. I never use it anymore unless we go somewhere with lots and lots of walking and want to have it handy in case dd gets tired.
I had an unfortunate sling experience, because back then I knew of no other slings than the "mainstream" Nojo one I bought at a large chain store and it only came in one size and was too big for me to adjust comfortably. If I have another baby I plan to get a better one and use it a lot more than a stroller.
I'm also horrified at the number of babies with plagiocephaly - the "flat head" kama'aina mama mentioned. I've seen lots of babies lately with those special helmets meant to reshape their heads. How much time are they spending with their head against a hard, flat surface, these kids? A woman I met through a playgroup once actually rocked her crying child while in the carseat on the floor - rocking the SEAT, I mean - as though the seat was a part of her child. It kinda grossed me out.
Bucket seats, strollers, swings, bouncy seats - they're all just things that have their uses, but it's moms who overuse or abuse them that give them a bad name, in my opinion! Just my $.02!