I have ProfileBuilder 2 and have looked at PlusSpec: two vastly different tools in terms of scope and cost — the only thing they really share is they are parametric and automate aspects of the modelling process.
In my understanding, PS has built a BIM-based object model for a construction-specific app, which creates smart objects (walls that know they’re walls) and enables automation and integration across the entire design/build process. Whereas PB2 is a general purpose parametric profile / assembly builder, that in theory could be used in any domain. (somewhat analogous to the difference between Revit and SketchUp)
PlusSpec has a database-driven backend that contains object, material and cost info (and includes data from real-world building products). Given that PlusSpec originated with a builder who wanted to be able to generate automated takeoffs from his SU model, that aspect of PlusSpec seems very comprehensive and robust.
The current version of Profile Builder has a flexible costing module that is fairly useful, in terms of available methods and reporting. It is as accurate and complete as the data you enter.
The downside is that you have to enter cost data individually (as attributes of an the profiles/components of an assembly), and there is no database support for uploading material or component information.
An option you might look at is Estimator for SU (used in conjunction with Profile Builder.) Their costing approach is quite compatible with PB from what I can see, but much more comprehensive. John Brock —the builder who developed Estimator— is a PB2 expert user and made several of the tutorials for building/costing construction assemblies in PB2.
He has also indicated that his next major release of Estimator will include database functionality. At $149 it’s several times less than PlusSpec, though it only automates costing/takeoff and not the entire process. Check out the intro videos: http://estimatorforsketchup.com
My issue with PlusSpec is primarily with the very high priced subscription model, which I can’t justify for our current workflow. I’m sure that it could be well worth it — if their embedded approach fits your needs and workflow — as it is impressively fast and comprehensive.
I can’t speak to what constraints PS might create for non-standard design and/or construction methods, but I’m sure that Andrew from RubySketch would be straight-up about whether it would work for your specific needs or not.
Hopefully someone with direct experience with PlusSpec and/or Estimator will pipe up to confirm/dispute my impressions. Hope it’s of some help at least.