I had DS there in the Home from Home and actually all worked out in the birthing pool, it was lovely!
But as I would expect in the NHS, fairly short-staffed for normal births, which was fine for me as I didn't really want any interference but just so you know what to expect. Since the birth was normal, DH, DS and I all stayed in birthing room together the first night and that was great (although DH did mention that the sofa bed was really uncomfortable).
I liked that the Home from Home is on the same floor as the Hospital Birth Centre so if intervention was needed you could move between the two pretty easily, otherwise I would not have gone for midwife-led unit as I was convinced I would have problems from my earlier ectopic, I thought it could be a bit like trying VBAC.
I was also at Tommy's about a year before DS was born, when I had emergency surgery for a ruptured ectopic and I can vouch that when help was needed I had a lot of staff sorting me out at once! After that I stayed in the normal ward which was nice, 4 beds but only 2 filled and plenty of space around, bathroom was fine.
So all in all I really trust them and hopefully will go again for another baby.
However will just mention if you are considering going private my friend really had a great experience with the Birth Centre in the grounds of St George's Hospital in Tooting, as she got same midwives throughout and said it was worth it even though she did have to have CS in the end.