I would go with best gauge possible that allows a breadcrumb or marks where you have been.   people on here state the trail pass at $200 is best money spent   but wouldn’t an extra $1,000 on a gauge they will own for years and that will retain value for your sled and possibly get you home safe be a good investment?    

for you, the 137 since you have no interest in tech.  will the gauge possible help with some return down the road, likely.  and if you plan to ride more as suggested, perhaps you might return to more saddle bag trips with your son, which I’d assume the 137 on the cat will give you more options for travel accessories to make those trips and bringing what you need much, much easier. 

I don't, but I will say I like the gauges on my 20212 more than that crappy looking sport gauge.  

137 , how long do you stare at the gages anyhow ? LOL!

Okay, if you had the choice.   129 - ( which I have ) - with G8 Gauge  OR   137 - with crappy sport gauge   I think I know... but love the conversation.