These projectors typically have no zoom at all, are incredibly noisy, and get very hot. They have very poor image uniformity, poor color reproduction, and very poor contrast ratios.
They are great as a 'fun project', but as far as an actual projector with an incredibly image, they don't even come close to delivering what DLP, LCD, and LCoS models can deliver. Especially considering how inexpensive current entry level DLP/LCD 720p models are running.
Front projection isn't just a big image on a screen...
It's a QUALITY big image on a screen.