I am still around. RL is busy.
I can share my thoughts about engine switch
*most switches would require a complete dev team
*UDK, I can only tell that the editor is crap
*HL2, editor crap
*COD4/COD:WAW, the best radiant ever, I managed to get first person weapon models in the game, pain in the ass, however, without Maya. Both are only scriptable which limits the options (e.g., no portal scopes), unfortunately the radiosity light maps are vastly inferior to mine with perceptual tone mapping. Particularly, COD:WAW engine could look really good at decent FPS.
*Cryengine3 dev Kit, just registered and looked at once, impressing, no experience otherwise
*Idtech4, no game ever looked good on it
*Idtech5, as far as I know it wont have full mod support (if at all)
*Xreal, if there will ever be a stable build for non experts ...
Otherwise I agree that ET engine would just need some minor addons with could be even ripped off Xreal or UrTbumpy or older Q2 engine mods, but I wasn't able to find someone who would be heading for such a simple project with realistic, reachable goals. Everybody wants the shiny complete engine overhaul (thats usually half finished when the next superior engine gets GPLed or a free devkit and the process starts from scratch)
I love down to earth practical recitations like this one. And in this case Coroner also pretty much sums up some of the reasons for the state of mod and indie game development we see today on these very same engines with: Thousands of UDK indie and mod projects stalled or abandoned, mostly derivative work with rough edges everywhere on HL2/Source (with a few dedicated exceptions), CE3 looks exciting but so did the CE2 MDK -- it may be years before there are enough people interested in working with it to support a team effort that gets real work done, Tech 4 stalled and nothing happening, Xreal will be Zreal before Xreal is in a useful form anyone creates content on no less a playable game...
Granted this is the hobby world of game development where the internet gives us a back window into every garage project which encompasses an enormous range of goals and intentions (or lack there of); but it shows to go ya that as far as the rubber meeting the road in results oriented development, even when it's slow going -- the Coroner's shop still is one of the longest burning and brightest brightest lights in the long night of independent game development.