I had a pretty bad time at GWH last year when I had my baby. I lost count of the number of times I was left alone in labour - twice, my husband had to go and fetch midwives to come and help me (once when I'd thrown up all over the room). The midwives varied from the woman who referred to labouring women as 'little girls' to the one who sat in the corner of the birthing suite, ignoring me and doing her paperwork while I was in transition.
So, I recommend taking along a VERY supportive birth partner as in my rotten experience, the midwives are likely to be busy, patronising or just plain absent. I did have one very good one at the end, called Meg, who worked out that my baby needed to turn and worked with me to try and move him; I only wish I'd had her all the way through. She also apologised to me on behalf of the consultant who sliced me up for the ventouse and ignored me when I was screaming, saying 'You can't feel that.' Apparently he is 'very good at his job, but has a dreadful bedside manner.' No kidding - I had nightmares about him on and off for the next nine months, and they only stopped after I went in for reconstructive surgery to correct the bad stitching he did.
And yes, I cried from the time they booted my husband out of my private room until he got back the next morning. Then I left against medical advisement because I couldn't face being in there any longer.
Final word of warning - all the women in my local breastfeeding support group delivered at GWH, and had their start in breastfeeding scuppered by midwives urging formula and warning of 'low blood sugar'. Unless they've changed a lot in the last six months, this is NOT a 'baby-friendly' hospital, so try to get in contact with a La Leche representative or lactation consultant before you go in.
I hope I haven't scared the bejesus out of you, but I think it's better to go in with your birth partner well warned in advance than to have him running around trying to round up medical staff, utterly bewildered the way my poor bloke was...