If you've already chosen the Lindo wing over the Portland then I'm not sure this will be much help, but I have had a baby at each and if I were to have a third, I would choose the Portland over the Lindo wing.
I don't think there's much to choose between them in terms of rooms or consultants (the Portland's are slightly bigger and have room for a fold out bed for your DH, while at the Lindo it's a reclining chair). I did gel more with my Lindo consultant but they are both highly skilled and reputable surgeons which is what mattered to me (I had EL CS both times due to gynae issues). FWIW, my c-section at the Portland was more complicated than the Lindo one but there was never an concern that it was not something they could cope with. I did ask my Portland consultant what the limit of their expertise/facilities were and his reply was 'sudden massive multiple organ failure'.
Food's better at the Portland by a long shot, the Lindo's more like upmarket cafeteria food.
The key difference for me is with the midwives. At the Lindo I found almost all of them a bit brusque and they seemed too busy to spend time with you. My meds were often late, one midwife told me I'd have to ride out the pain when my consultant had told me the specific drug I could have, and their breastfeeding help was rather perfunctory. At the Portland I had pain relief on tap and they have a dedicated lactation consultant to help out as well as the midwives. One midwife spent nearly an hour helping me get my son latched on.
I also found the Lindo Wing to be a bit sloppy - they lost my NHS notes, including my scan photos, and didn't give me my discharge notes for the community midwives so DH had go back that evening and collect them. I also ended up making a complaint about a staff member (LB) for which I received an apology from Mary, the business manager once it had been investigated.
I realise that these all pretty much first world complaints and I was very happy to be in the Lindo wing rather than the NHS, and if it's your first birth, you're unlikely to be thinking that you're missing out by going to the Lindo!