so, I have decided to go with a different module most likely.  With one of my groups, after looking it over, I'm really wanting to add in the Tower of the Stargazer as a potential thing for them to run into.  With another group, I may have to run DFD eventually still. 
Reading Stargazer though, looks like it could run great as just an odd random encounter that takes up a session (or maybe two depending on how long they decide to take to explore it).
Plus I can't help but think of a certain Rainbow song I really love while reading through that one...

Hmmm, well, that makes DFD sound like an ideal option for a one shot that is not going to continue on into anything more, though, grievous consequences for a world can be quite fun to see play out through a longer campaign depending on specifics.

Oh, that definitely is a feature of PF (if you run it completely by the book at least), it is strongly built to be in favor of character survival I have found. You are also right that a lot of PF players don't accept characters dying or having other horrible nasty permanent things happen to them very well (I've encountered such players and hear of many more, so they seem to be the norm).

Well, I had one character lose a limb (permanently) and then get killed (pretty horribly). Others are dealing with... other consequences at the moment.  I wasn't 100% sure what the response was going to be since I hadn't been quite that cruel with one of said player's characters before (at least that I can recall, I've gamed with them for a while now), and fortunately it was positive and my discussion with my players has led me to conclude they really are gluttons for such punishment.

You are very right that a more "hardcore" DMing/playing style does take a mental shift too though. 

I am actually tempted to outright run a LoTFP adventure using PF rules with some houserules at some point (rather than just drawing inspiration from it for a few sessions), it would be excellent as a one or two shot game.  I really like Better than Any Man, though, think it might be hard to run that one in just a few sessions.  I have not read over Death Frost Doom yet.  Is it shorter?

So, I haven't played LoFP yet. But I was recently introduced to it and decided to get a few of the PDFs.  I've been running my own historical fantasy campaign using Pathfinder for a while now, drawing a lot of inspiration from history and mythology.
 
I read through the PDFs and couldn't help but be influenced by them and that has proven to be a good thing. 
I had a player recently tell me that I've actually managed to give them nightmares and this fills me with a sadistic glee.  Being able to shake a player up that much makes me feel, rather successful as a GM.

But along with my other inspiration sources, even if I'm not running LoFM I definitely have to give some credit to reading those new PDFs.   So, I very much give the setting kudos.