A possible third way: if you’re headed toward running local LLMs, configure a MacStudio for this purpose, get the Air in the config you desire, and use a VPN connection (I prefer tailscale) between the MBA and the MacStudio. You get the light weight and the heavy compute.
It certainly isn’t the cheapest option, but it seems to hit the features you were considering.
One note – if you’re going the local LLM route on the MacStudio, the M3 Ultra is more performative than the M4 Max due to the processor interconnections being higher speed for the M3 Ultra.
FWIW, it’s the doubled memory bandwidth on the Ultra that enables LLMs to run faster. My M1 Ultra outperforms the M4 Max because of the doubled memory bandwidth.
It’s crazy that a first-gen processor outperforms a fourth-gen processor in this specific use case.
Personally, I’m not fazed by the whopping 4.7 lb. of the 16" MBP, but then I do a lot of weight training. Seriously though, I really like how solid and substantial the big MBP feels (not to mention the better performance), and the weight has never been an issue in my backpack or otherwise carrying it around. Of course, everyone has their own threshold. Even in the case of the 15-16" versions, the difference is what… 1.2 lbs? (delta for the small ones is even less). That’s a couple mildly indulgent meals for most.
I have been carrying my 14-inch MacBook Pro more recently in a nice WaterField computer case, back and forth from the office each day. It dawned on me that for decades, professionals carried relatively heavy briefcases or leather satchels filled with papers between office and home. Our computers carry an entire office of content and whole digital libraries with less weight than the professionals of decades past. I used to lug a Compaq computer through airports. Perhaps we are spoiled.
Since we are remembering. My first portable computer was Commodore SX-64 that my Dad purchased for me as a gift. Good thing I was young. This was heavy but at the time I thought it was cool. According to Google, it weighed 23 pounds.
Usually just on trips out of the house to relatives or business trips. Otherwise, it stayed on a desk. This was one of the first “mobile” computers. It was a HUGE deal in the early 80’s.
The weight was unpleasant. The actual limitation was the size. I usually travel with a bunch of camera gear and my laptop in a backpack. So the laptop would be in a sleeve on the back panel. I can fit quite a lot of camera gear into packs that are simply too small to hold the 16” laptop. So yeah, 500g isn’t huge, but 50mm is.
As soon as I had it out of the bag and open, I loved it. Unfortunately, I did not have the services of a Sherpa.
All sage advice. I am a victim of marketing… must have the best screen, better sound, etc when in reality I prefer to use my IPad Pro for such dalliances!
The only quibble I have with your excellent comments is the recommendation to drink Fosters! Fosters was again a great global marketing campaign but most Aussies are beer snobs ( not me- rarely drink beer) and wouldn’t be seen dead with a Fosters in hand!
It must have been a good marketing campaign because it is the only beer that I remember from my time there some 3+ decades ago. To which, I can add a joke.
The CEOs of Budweiser, Fosters, and Guinness are relaxing after an exhausting convention. The Budweiser CEO says “Give me a Bud, the King of Beers”. The Fosters CEO says “Give me a Fosters, the Amber Nectar”. The Guinness CEO pauses for a moment, and then says “Give me a diet Pepsi”. The other two look at her in shock. To which she replies, “Well, if you two are drinking lite sodas, I should too”.
The Germans in the room can substitute the Hefeweizen from Weihenstefan for the Guinness to the same effect.
. Great joke and probably a truism re “kick”. European beers can be very heavy and super strong.
Once went to a Belgium Beer pub…one beer later…very light headed
Fosters was heavily marketed in Australia but never took off as much as it did overseas… Surprised no one harassed you about drinking a “Sheila’s beer” when you were Oz. We are a very mature lot…
Seriously though, I really like how solid and substantial the big MBP feels (not to mention the better performance), and the weight has never been an issue in my backpack or otherwise carrying it around. Of course, everyone has their own threshold. Even in the case of the 15-16" versions, the difference is what… 1.2 lbs? (delta for the small ones is even less). That’s a couple mildly indulgent meals for most. 
