Warlords and Pupae and Flies, oh my!
I have never been able to lead a monster around a map like you must have led that Warlord! I'm still trying to figure out how you could have gotten him through the doors of that temple. As far as the flies and pupae were concerned, this is one of the things that made this map pack harder than many others. I have never seen anyone tweak a monster's properties to make it FASTER before!
Oh, and I play most of the maps for Unreal from inside UT with the Oldskool Amp'd mod, so I have few if any problems with overwriting older saves.
Also, I usually start off at Medium difficulty and play it again on Hard after I learn most of the secrets.
Strangeworld was a fun map pack for me simply because it had a good supply of Mercenaries. I think that this is a monster that is underestimated by mappers and coders. (BTW, if you hadn't noticed, my avatar is the face of a Mercenary Elite.) I typically find Mercenaries and Skaarj Lords to be the hardest "mid-size" monsters for me, because they're very unpredictable.
Skaarj Berzerkers are easier for me because it's not hard to tell what they're going to do. They're particularly easy if they're in pairs, because it takes so little effort to turn them on each other.
I just finished a map pack called "One Day," and I was rather impressed. If you try it out, don't forget to remove Dusk.unr from your Maps folder when you're not playing this set of maps, or Dusk.umx (the music from NyLeve's Falls) won't work.
Also, if you like a TOUGH challenge, you might want to check out a small map called deCyberDuel. The UT version is pretty hard, but the Unreal version is nearly impossible to finish!