I'm not 100% happy with my lelo vibe, the Mia, but that's largely because I made the leap and got one it for my very first toy. I didn't know what I needed out of a toy. It's great quality, I've never had a problem with it, doubt I ever will, and I'll probably continue to use it. However, now that I've had it for a bit, experimented, and done research, I realize I'd much rather have a toy with different features.
My next vibe will still be lelo, though, (probably liv... or gigi... or elise... or alia... or all of them) because I trust the brand. I have no interest in cheap toys that I'm uncertain of the quality of.
Also, as someone above said, batteries can get expensive after a while. Just being able to plug it in is NICE.
Another point: "not strong enough" is very much a matter of opinion. Do a discussion search if you want to hear people gush over the gigi (pun intended).