I think this is very helpful Nathaniel.  The reality is Sketchup never set out to be a program for Architects or Designers.  It has just moved that way because it was such an intuitive excellent 3D drawing program to start with.  It is also much cheaper than alot of the software out there in the marketplace which gives it a certain appeal.  There is no doubt that a high-level user has to develop a good workflow to get around some of the inadequacies of the software and make it efficient.  I think in the long run, as developers add in functionality, SketchUp will become more and more competitive.  I think Trimble would be wise to invest some time into Layout as this is where most people come unstuck.

I think in Nick Sonders Case the nature of his work (high end, custom homes) means that SketchUp is the best option because alot of his building practices are not easily automated.  For someone just drawing up standard houses much more automated and specific software probably is better.  Personally, I love the open source, evolving nature of SketchUp and the fact that it is the underdog biting at the heals of the big boys.   

The other huge advantage is that the customer can look at the model using free software which will work on nearly any computer.....this has been huge for me in my business! 

I sometimes get pretty frustrated with Layout but I have found that over the years my techniques have developed to streamline things.  Michael Brightman has an excellent system which really helps at the layout end. The main issue I have layout is with the limitation of the dimensioning tools.  It will be awesome when this becomes automated and removes the risk of "snapping" to the wrong place.

One potential issue I see is that there are all these developers producing plugins which do specific things but don't necessarily work together.  The user usually still has to do some legwork in getting everything flowing.....this is certainly an advantage of the big players.   Excuse my musings and feel free to delete them if not applicable to this forumn.........I just love sketchup!!

I think one thing that is perhaps forgotten in all this is that to model something in SketchUp properly using non-parametric tools the user must actually understand construction well.  With fully parametric programs the user is able to create a heap of geometry with very little knowledge of the actual real use and purpose of that geometry.  Although many find this frustrating when using SketchUp I think that ultimately it means that accuracy is increased and mistakes are avoided.  I am a builder by trade and when I draw in SketchUp I am literally imagining myself on-site building with my hands.  This means that the end product is a true digital representation of what will happen in reality.  I think this is the beauty of the free-form modelling - it requires the user to actually build step by step producing better results in reality!!

I also think another thing to consider is not just the ease of creating geometry but how this is then going to be communicated to third parties.  Drawing a model in SketchUp is one thing but presenting and communication that digitally and on paper is another.  Ultimately the model must be organised in such a way to allow for ease of documentation, customisation (as variations occur) and also ultimately quantification.  Builders always need to know what to build, how to build it and how much it will cost.

You said it far better than I could.....exactly my thoughts!!

I think that it vital that the user can add in their own custom items to a wall assembly.  It is also vital that these items stay there on a regeneration of the wall.  Other plugins I have used reset on the Regeneration which is incredibly frustrating!!

There are definitely standard approaches to construction however it is often for the non-standard that 3D modelling is most useful.  I think the key is to think carefully about the balance between something being parametric whilst still flexible and fast.  I personally find it pretty frustrating when I am locked into a completely parametric system which makes modelling natively in SketchUp difficult or slow.  Someone who has good sketch-up skills will always want to be able to use those skills when something falls outside the normal parameters. I hope this is helpful.