Hi BA FTers.
I'm flying from ORD, and going to Rotterdam, Netherlands in October. It's a quick 4-day weekend trip so am trying to plan things out ahead of time.
I'm using AA miles (only 20K starting 15OCT off-peak).
Here are my options:
1) ORD-LHR-RTM (Either 6 or 9 hours at LHR) arr. RTM directly at 20:10. I am open to going into London and having the day there.

2) ORD-LHR/LCY-RTM (4:10 between flights, change airports from Heathrow to London City during late morning) arr. RTM directly at 15:30
3) ORD-LHR-BRU, good 2 hour connection at LHR, but then 2 hours train to Rotterdam (around EUR50)
4) ORD-LHR/LCY-AMS --because it's also via LCY it's less preferable to the direct RTM flight.

I'm leaning toward Option 1, checking bags through to RTM, and enjoying a day in London, and having some drinks at the BA lounge (I'm BA Silver, thanks to BMI, but rarely have flown BA!)
But if the Option 2 LHR-LCY connection isn't too harrowing I'd be open to doing that, giving me a decent arrival time into RTM. I looked online and it seems to involve 3 or 4 changes of tube lines and/or trains, not super fun with bags I'd assume.
Anyone have some advice? Thanks!