Yep, they have a very poor texture loading scheme..
To elaborate :
I was running on 512mb Athlon 2500, Radeon 9700 Pro, and was experiencing VERY laggy play.
Running around looking at the ground the game ran at full framerate, but as soon as I raised my head it was like running thru treacle. The graphics, whilst nice, are nothing to overly stress my videocard to this extent - so something was amiss..
Deep-Shadow helpfully (accidentally?) left all their debugging symbols on the DVD, so I booted up the game in Dev Studio - and every time the game lagged, it coincided with a load of..
"C++ exception..blah"
"Loading Texture..blah-blah"
..messages in the debugger.
I then looked at the "precache.txt" file in the game directory, and noticed that on all memory configurations of 768mb - 2048mb+ it ensures that a huge bunch of textures are loaded into main memory.
To conclude - the game has a really poor pre-emptive loading scheme. Most well-written games will load up the textures & models it needs several seconds before it actually has to render them.. But this game doesn't load its textures until it actually comes to drawing them.. If the texture is not on the graphics card or in main memory, then a C++ exception is raised when it comes to rendering an object. The exception is then caught and the texture/model is loaded.. Hence why a faaaaast or defragged HD might make things a bit better.
Anyway, I liked the game so much that I upgraded to 1.5gigs ram - and hey presto, silky smooth gameplay.
Hope this helps
CW