Its about time we decided to disagree about these two again!
We stayed last week. As a background, my partner never really liked the MO BKK, felt it was too stuffy and boring. I liked it but at times I knew it was far from perfect.
So, we took the plunge, crossed the river and stayed at The Pen.
We stayed at a Grand terrace suite but to be honest, the suite did not make or break the stay.
Service was excellent and not over powering. Yes we wore flip flops and shorts in and out as we did at MO previously (I do not apologise for being somewhat casual in BKK, I am paying to stay there, I find the heat stifling at times).
The pools at the Pen were more relaxed and the views from the suite were wonderful.
The boat service to the skytrain at saphan Thaksin is excellent and you may as well be on the 'other side' of the river.
We will stay at the Pen again.