How can I speed up the removal of stubborn tile?
With these types of tiles you do not want them to break as they are harder to demo when they are in bits and shards.  If you try to use a scraper (even power) what inevitably ends up happening is the top of the tile comes off, leaving the much harder to remove bottom on.  Also this method severely damages the subfloor, sometimes to the point that you will have to put a new subfloor in.

What you simply want is a mallet or a hammer.  Let me be really clear since I have demo'ed at least 50 of these bathrooms now and I think I have it down to a science.


Start in a corner.
Hammer the edge tiles flat.  When I say hammer, imagine that you are playing drums in marching band, not hammering a nail.  You want some force but not enough to break the tiles (they are usually hard to break when striking straight down).  Bring hammer up 8-12 inches with each strike, hitting a small area repetitively.  
The first couple of rows might take 20-30 taps for a small group of tiles.  This method does not "remove the tile", it removes the thinset bond to the subfloor.  The tiles will just disengage from the floor.  
Don't just tap right at the edges.  If I have an edge then I am tapping in a 6-10" perimeter in the area.  
Clean-up is easy since most of your tiles are in one piece.  I can usually get a decent size floor demo'ed and cleaned in 2 hours this way.  


Note: One of my contractors does this via air compressor and flat air hammer bit.  After I showed him the method he went and got a flat bit that I think was made for pounding out auto bodies.  You have to be careful with this because the force sometimes is too much or too repetitive and it will crack tile.  I personally don't think it is faster but you could argue it is less labor intensive - he spends more time cleaning up.  The hardest part about this type of demo is on your knees (I would pick hammer/knee pads over compressor/hammer bit).