Well on the Predators Thread I think myself and Turd Fergusen hit an interesting topic, so instead of going off-topic on that post I decided to do a spin-off here.
See my note on overspecialisation. I totally agree, it all depends what else is in his army list, without that information we can only give personal preferences (mine would be ditch the preds and use dreadnoughts, but then I don't like Preds).
You bring up an interesting point. In my opinion the Games Workshops game designers have done a fabulous job of creating a truly flexible game that allows the player to build his/her army without too much fear of building a "lousy" fighting force. So it distresses me to see players asking other players "Which is better? The Assault Cannon or the Cyclone Missle Launcher?" as if there were a "correct" answer. The only true answer seems to be something along the lines of "What do you want to do with it? What will be supporting it in that task? What will it be up against?" which leads to very complex discussion (which I prefer, by the way...) ending in "Oh, so neither one is really 'better', they simply both serve different purposes."
Then we all go have a beer and tell war stories.
Dang, anybody want to play?
This I think is one of the things that becomes annoying on websites, the 'Who's the best?' questions, and the 'Is this better than that?'
However most people new to the site/game usually quickly learn there is no 'best' this is a game that GW has done very well in balancing (in most cases) in that there is no one 'best' army. That is a huge amount of personal prefference, something I love about the game. You can personaise your army to huge degrees, this in effect makes you 'God', the GW police don't exist. so they wont come in a smash all your stuff for doing something crazy.
Anyway, a bit vague in parts but any comments anyone else wants to add?