I've had both. DD loved the swing, but like you said it wasn't portable. However, I'm a baby wearer anyway so having somewhere for her to sit wasn't usually a bog deal as she had the best seat in the house . For her I also had a rocker and a bouncer. The bouncer won hands down over the rocker, though the rocker was only a cheapie.
DD grew out of the swing at about 6 months but we used the bouncer until she was almost 1 and too fidgety to sit in there safely.
Both bouncer and swing had a toy bar, but often a well placed mat (ie near a window or mobile etc - something different to look at) does exactly the same thing.

Poor DS didn't get a choice as he only had a bouncer. Both my bouncers had a vibrating function but TBH I never ever put batteries in there once....don't know why just didn't see it as a necessary function.