Ok, no replies as of yet. Looks like I'm going to have to work this one out myself. I've ordered two Move 2s. Hopefully they'll arrive tomorrow and I can carry out my own test and decide what stays.

Exciting!  

Sonos move 2 has 2 tweeters pointing out in different directions, so that the soundstage on a single speaker has better capabilities of sounding in stereo. There isn’t a great deal of difference in sound in my opinion as a Stereo pair.

move 2 has 24 hour battery, when your battery goes dead you can buy the battery packs for Move 2 for a Move one, the battery will not be 24 hours in a move one as the battery optimisation in Move one is not as advanced as the Move 2. But I’ve heard using a Move 2 battery in a Move one will give you about 17/18 hours of battery. 
personally I wouldn’t worry about it until your batteries are depleted, at which point buy new move 2 batteries.

on a totally separate note, I run two move one’s in stereo and two Roam SL’s also in stereo pair, sound bloody amazing, by positioning 4 speakers around a room or two outside and two inside.

I'll be testing:

Move 1s in a stereo pair versus Move 2s in a stereo pair. I don't recall seeing much about this from someone who has actually done it.

I'll also guage my own view on the relative difference between a single Move 1 and a single Move 2.

Having better sound from a single speaker has it's benefits as there will be times I'll just take one, but can't bear the thought of it being mono. Also, in a room where you sit nearer a one of the speakers, I wonder if a group of Move 2s would be better than a stereo pair config.

And then there is the battery. I had the music playing probably higher than moderate levels and the battery on my Move 1 drained quicker than the claimed battery life.  I presume the Move 2 will do the same but still should last way longer. So that is a plus if you have an an afternoon/evening event planned. I don't want to worry about the battery. Battery anxiety is real! And I don't mean the usable lifetime of the battery, I just mean the runtime.

But of course, there is a significant difference in price.  So I'll have to make a decision.

I'll post back here with what I find/decide.

And heck, I might try the pair of Move 1s in a stereo pair plus the pair of Move2s at the same time, just for fun!

The results are in! 

In terms of single speaker performance, i.e., a Move 1 versus a Move 2, the difference to my aging ears was minimal but noticeable. The Move 2 had an edge. Maybe it was just slightly louder or the sound stage was slightly bigger. It did appeal to me more but if the Move 1 is considered good, the Move 2 sounded 'good' +1. Nothing major. But my hearing isn't great and I'm no expert.  I tried to listen at low and loud volumes, inside and outside of the house.

In stereo pairs, the sound from both sets of speakers was much better. Not just louder but the stereo separation was really present, as you would expect. Again, the difference between the two pairs was minimal but the Move 2 kept the same edge to my ears.

The slight improvement I found would not be enough to justify the big difference in price however. A Move 1 is £299 whereas a Move 2 is £449.

Battery life is a big concern for me. So a big win for the Move 2. The other small improvements to the case and line-in are nice to have but not really of much value to me.

The Move 1 having Google Assistant is a big plus for me and losing it on the Move 2 is a pain.  90% of the time the speakers will be resting on their charger in the lounge, where I currently use Google to turn the lights on and off etc.  Having the Move 2 in their place would mean I need to add a separate Google Nest or something.

But given this purchase will last a long time (I hope), I think I'll go for the Move 2.

And yes, playing two stereo pairs of Move speakers together is good fun and LOUD :-)

Hey if money is not a problem go for the Move 2, lol. They’re gonna sound better with an extra tweeter and battery optimisation is far better. Agreed if money was an issue at £299 the Move 1’s are still a great speaker.