We have several working mechanical sets at our museum, and I can assure you the pictures are not very good. And the pictures are far better than they were in Baird's day. We use a standards converter to create the 30 line images from NTSC. Baird used a mechanical camera. We have direct connection from the source to the receiver, while Baird broadcast on the AM radio band, with all the interference problems. We have a direct connection for sync, while Baird's receivers extracted the sync from the video in a way that cause loss of sync whenever there was little white content in the picture.
There are several surviving photos from mechanical receivers from the 20s and 30s, and they all show very poor quality images.
http://www.earlytelevision.org/western_41_pictures.html
I don't think Baird ever had a viable entertainment media with his 30 line system. This is the main reason that mechanical broadcasting ended (with a few exceptions) by 1932 - it simply wasn't good enough for entertainment purposes.
The only possible exception was the Scophony system, which was capable of high resolution. This didn't solve the camera problem, though. There were higher resolution flying spot scanners for use with film (Baird's, for instance. Also one made by Harry Lubke:
http://www.earlytelevision.org/w6xao.html), but nothing that would work for live television.