WCC, stoked you're hooked, you wont look back

The Naish Nalu line has not had many huge changes for quite some time now. The physical mould is identical for the past 4+ years (asside from using the GTW bottom mould on the 10'6" GS to add thrusters of recent years). So the boards are the same in shape in every way. There has been a few minor changes to look, graphic and the like, but in general you're getting the same awesome board every time. Recent years I guess have shown the biggest change which is the wood sandwich that has not gone to a high quality bamboo (not the usual cheap china rubbish you see out there) from the Australian Pine of <2017. This has dramatically helped in maintaining an unmatched strength to weight ratio at an awesome price.
Bottom line, you can't go wrong on a Naish. Apart from the board being amazing and proven year after year as the #1 go to longboard SUP, the backup and support (especially here in . AUS

) in awesome.
BTW, size wise. I am very similar dims to you and ride the 10'6". It can be a little wobbly, and the 11' is definitely noticeably more stable, especially on the smaller waves - so good choice.
Enjoy, Ride safe,
JB
Here's a vid of me enjoying the glide 5 years ago on the 2014 Nalu GTW 10'6"