That said, swmbo and I will get one of these LISA's each as they are contractually bound to let you have the cash at 60, whereas there is already talk of pushing the private pension age past 70 or even 75 for someone my age 
Govt legislation trumps contract law. It will be just as easy for the Govt to up the LISA age from 60 as it was for them to up the Personal Pension age from 50 to 55. I'm afraid trying to second guess what a future Govt may do is pointless; you have to play by the current rules. For that reason I see little benefit in LISA's @60 when the current Personal Pension age is 55 with 25% tax free cash. If you're a 40% tax payer, stuff your PP with as much as you can afford, If you're a 20% tax payer the case is less clear, but I'd still prefer pensions over LISA's
My understanding is a bit different, LISAs are a contractual arrangement between you and he provider. The government hands over the "bonus" 25% to the provider at the end of the tax yr in which you make the contributions and it is then yours. However if you withdraw pre 60, the LISA provider is bound under the terms to deduct 25% plus gains from the amount you receive. While I agree that they can change the rules (of course), this structure makes blanket changes harder.
Having said all of that, I haven't signed up for one yet so haven't had my nose in the details yet.
There are also a couple of other points worth mentioning. The lifetime allowance has taken several jumps down in recent years and I reckon even at current levels I'll hit it at some point, so I may as well have the "bonus" cash as hit the lifetime allowance a few years earlier than I would otherwise.
Also, under current rules ISAs of all types are tax free on withdrawal, which is nice if you are likely to be a pensioner paying higher rate tax.
With all these types of things, diversity is the key. I can see a pension pot being a main source of retirement income, but there should be some other assets in there too.
Talking of pensions, as you seem to be quite well across the subject, are you aware of any way to pass a pension pot between spouses before retirement? Due to the nature of our work I'm currently accruing the majority of the pension assets and SWMBO very little. The only way I've come up with to "pass" the assets between us is to divorce. Or for me to die, which seems a bit extreme