Another difficult puzzle ( very very difficult ) is the 8x8 difficult of today 22MAR2012). I gave up. And the degree only 72? The modules are the more difficult puzzles and the configuration of today aid to render more difficult.
The 23MAR2012 8x8 is rated 76.2 and I solved it much more quickly than yesterday's. In addition, it has been solved 114 times in 17 hours while yesterday's was only solved 60 times.
Yesterday I got hung up on the 128x for a while, but couldn't come up with anything definitive. I finally made some headway when I focused on 14,+,d4d5e4e5 in combination with 20,x,c4c5 and 15,x,d2e1e2. And then I probably made a complete guess before finally finishing it. I honestly don't remember because it had been such a slog up to that point.
I bet that if you start solving from the correct portion of the grid things would fall into place fairly quickly. Thus the 72 rating. I was just naturally drawn to the 128x since it was necessarily composed of 1s 2s 4s and/or 8s and that seems to have been the wrong choice.
For instance, maybe the 1mod cages in columns b and h are a counter-intuitively good place to start. I shied away from them since there seemed to be so many possibilities.
When all is said and done, I think Patrick's solver is just smarter than me. :)
On a tangent, should this discussion be in "Specific puzzles/your own puzzles"?