<<Trying to decide between a new Arylic "Sunbrella" type or OEM German canvas
for my top.

Though I'm still not sure which is more water resistant (acrylic or properly
treated/maintained canvas) when we talk of "breathability", are we talking
about how well a material helps keep the interior cooler in hot weather or
which material dries out faster after getting really wet or both?>>

Hi Neil:

In terms of durability, Sunbrella will outlast canvas by a good margin. It used fairly extensively in the boating industry for boat covers and such.  I do my own sewing, and have made a number of bags out of the stuff, and it is extremely durable.  It sheds water very nicely, but is not waterproof.  It was truly waterproof, then it would not breath.  It really takes a whole lot of water to get any kind of seapage through it at all, and it dries out very fast. Sunbrella is also solution dyed.  Think of a carrot versus a radish. Sunbrella is like a carrot in that is is dyed all the way through, whereas most fabrics are like radishes. The stuff doesn't fade or stain to a noticeable degree, unlike canvas.  It is stiffer than cotton, so it may not tuck under the pop top as easily, but I really don't hear that many people complaining.

For a very nice tent, check out   http://www.atelierspk.com/west_english.html

This guy is very well respected.  It's the same company that Benny Boy used for his van.  The quality I've seen from Go Westy is horrible.   If you're going acrylic, go with this guy above.

Cheers,

Troy