Inflatable Penis, if you haven't read my review on it yet then dare to do so!
Inflatable Penis is stated to be stronger in the main rating, and indeed, it is cheaper, versatile, and if you like the idea and already tested it then you can go on for one for anal pleasures with the Wonder Plug...
God forbid it's weaker...
^^
I would recommend it as a vaginal vibe if that is the primary purpose for you, and yep, after that I will get the Wonder Plug...