I read this thread with interest as I'll soon be looking at a similar coach as the OP described.
To the posters who choose a favorite (Allegro or Dutch Star) please explain why you recommend that coach. If you don't explain why you are recommending a certain coach then your opinion carries little weight.
Interesting post by Dahkota concerning the size restriction on 42' coaches at some national parks. Not one else commented on that! Most folks on this and other forums have consistently stated that size restrictions are not an issue and in the rare case they are, can be easily worked around by finding a nearby private park.
Personally if a size restriction is going to restrict visiting some or perhaps several govt run parks I would opt for the smaller rig. Is a 42 that much more comfortable than a 40 - not withstanding the tag issue.