I'd agree that there's not much to choose in terms of academics - the data shows that all these schools do very well in terms of results, so would think you are in good hands on that side, with whichever choice you make.
For us , CLSG has been excellent - we moved from an independent local school (through school) in year 7 (currently year 9), and couldn't be happier. Yes, the school is quite academic, but I'd definitely want to make sure to point out there is difference between a high pressure environment and one with high expectations, and I'd personally say CLSG has been the latter for us. And those high expectations don't just apply to the very academic subjects - I feel my daughter has been challenged (in a positive way) in drama, music, DT, art...in nearly every subject really, with the expectation being not always so much on results, but on critical thinking, reasoning and a considered approach to whatever they undertake.
We have a ~50 min commute - initially I expected this to have to put constraints on sports and extra curriculars, but have been surprised by the amount of opportunity there has been - cricket, tennis, athletics, choir, robotics, fencing - these are all after-school activities we've had going on over the last few years. I won't say its easy - typically clubs run for an hour after school, so means getting home at 6/6:15, and then dinner, homework and a lot of topic tests throughout the year means we experience frequent late nights.
In terms of facilities, I find the space has been used quite innovatively - particularly in spaces for musing, drama and other types of performance - and I felt comfortable with what I saw when we first visited. Off course there is a contrast when you see some of the larger (space-wise) schools, where you can see the new £10M library or sports facility, but ultimately it came down to vibe and fit, and CLSG just clicked for us.
We started after the new head joined (only encountered the previous head at the open day), so I have no real reference point of how things were. As far as I am aware, there hasn't been and noticeable staff turnover in our time - however, I've experienced this in my own school days, so appreciate how disruptive this could be, but I have no fear or visible signals (touch wood) that this is likely to occur in the near future.
All the best with your decision - the other schools mentioned in the thread are also fantastic options, so I don't think there is any right choice here - I truly believe that 95% of children and parents are happy with their choices - again most of us don't have another reference point so we buy-in to the vision and immerse ourselves in that environment. All the best, and feel to PM if you have specific questions.