Gauge - It's Much More Than a Number

I've just finished Banging out a Carbeth.

The original design was knit with a double strand of Buachaille, a yarn that I have yet to have the pleasure of working with - therefore I don't know it's particular qualities.

The pattern gauge is stated as 3.5 stitches to the inch.  

What is unknown is the actual fluidity of that fabric - that best suits the design 
as it was intended.

Two Swatches

Log Cabin A Long with Rowan Kid Silk Haze

(a swatch that just happens to be right here)

Carbeth with Quince Osprey

Both of these fabrics measure approximately 4 stitches to the inch, 

but are a world apart in everything else.

Just where am I going with this?  

As happy as I am with my dense-ish fabric sweater, 

I think that I would have LOVED a lighter weight yarn knit in a more open stitch.

 Perhaps this beautiful Romney Worsted from Prado de Lana?
It's perfect.