How much better is in-house than private practice (US/MC firms) in terms of work-life balance? How much of a pay cut is it?

As above - just want to see what I'd be getting myself into if I decided to pack it in.

Not even qualified yet - just trying to see what options could be out there at various PQE points!

It’s difficult to generalise about in-house.

you could be a one person general counsel and general problem solver or a cog in an enormous legal team. You could be working for a ftse 100 or a start up. You could be working in financial services or something immeasurably more interesting. 

If you go in-house at an IB, the work-life balance is better than PP, but its not a walk in the park and if you progress and cover a lot of landscape you will face time pressure and stress.

You wont pull all-nighters or weekends (unless the world is ending which occasionally happens but not v often at all), but you can pull days of rolling out of bed at 8.30 am and not moving from desk until 9pm if you cover multiple time zones and have a largish empire. 

Pay would be a bit of a step down from a Yank firm (as they make silly money) but you could definitely be on like 120/130K as a middle of the pack VP with 10-20K bonus - if you make ED or equivalent you can push £170 to early £200s with £20-30k bonus, but you will be working hard at that level. 

Your days are shorter but you end up more exhausted from the constant hassle - pinging, emails, calls etc. a nice quiet day to draft and read seems like a relief from the constant doctoring at times. 

I enjoy it (especially when working with one of my shit hot business who lead their field and its cool being a part of their machine to be first to market) but you need to know your risk tolerances and be prepared to be much more client facing than private practice and push back on the more antagonistic denizens of your desks.  

Bidbad sums it up really well.

I made the jump but once I was already at a pretty senior level. My days are on the whole still long, but the pressure is different and feels better to deal with. I have much more control over my work There are pay disadvantages but I still make six figures and see much more of family and friends. I never dipped my toe in the US waters because I am not a masochist but if it is riches you want then in house will not float your boat - if you want a comfy work/life and objectively good salary then in-house is great. I wouldn't go for it until you are at least 6PQE however  

Also completely depends on industry. I left a private practice funds team to go to a client and took a 5k base pay cut but got double the bonus, so overall a pay rise.

In my case, infinitely better. Work in PE, get paid more than a lot of law firm partners and see my kids every night/have a social life. Pressure is very different. You’re more at the coal face so crises can blow up quickly, but you’re not pulling all nighters. 

Its much better in terms of work life balance where I am, proper 9-5 job, but I've never worked so intensely or had such decision making stress.  

Looking at the RoF salary tables, I'd say a 20-25% pay drop, probably getting up to 35% the more senior you are.  However, we get pretty good bonuses here in the 20-40% range which are virtually guaranteed, so its difficult to say after those are factored in.   

It’s difficult to generalise about in-house.

This in spades.  Even out in the sticks, there's a lot of variance across industry/sector, size of company, size of legal team, maturity of legal function etc etc.

I'm probably on 20-30% less than my last PP gig but for 20-30% of the hours and no boss, so....

bollox at no boss

u might not have a lawyer as a boss (deffo a bonus) but not no boss at all

Try to steer yourself towards private funds/equity in-house.  It can be pretty lucrative and decent ish hours.  

One point to add that I haven't seen mentioned already - once you reach a certain level in-house LTIP / share grants are pretty common, particularly in US-owned companies. They can be a damn good way of boosting salary. Admittedly there can be a good element of luck in timing the share prices if you work for a business with a volatile share price, but can lead to some pretty substantial numbers.