I've been using a glass infuser for months, it really isn't easy to clean. The slits in the bottom inevitably get stuck full of tea after every steeping. The only teas that don't clog the slits are made up of large leaves, such as oolongs. Kela is right, they're very fragile, I have chipped and cracked my infusor without even knowing.
I also have a ceramic infusor which is no good because the holes are so large that even whole leaves are let through.
The only thing I've found to stop reasonably all tea leaves is a mesh filter.