Spent that last 8 days with the family in London at the Park Lane.
I was quite impressed.
If you have read some of the comments on tripadvisor, (and here) it sounds like it could be hit or miss. However we had a great experience.
Location wise, it is near great shopping and next to the Tube, which is a great way to get around London.
I requested two adjoining rooms and that happened, making the trip much easier.
While the executive lounge is not giant, it was never too crowded for us. The hotel employees were always ready to help with any requests we had.
The only thing we dislike, and I think is common to the UK, is that there is not power in the bathroom for a hair dryer. Likely an electrical code issue (have seen that at other London properties). The only plug/mirror combination that would work for my wife was to plug in by the nightstand and stretch the cord under the opened closet which had a mirror. They could easily put a mirror by the desk and problem solved.