The view from a room on the river side of the hotel is worth paying the extra for.
The rooms are spacious and comfy, with great beds. You can also use facilities at the sister hotel only a few hundred meters away.
Staff are friendly and helpful and food at the hotel is better than usual hotel food. I am guessing it's pricey due to the location but since it was on business I didn't see the rates.
If you are looking for a hotel with views in London and good all round service then this is it.

Went to Europe for a month and spent the frist week in London. We stayed at the Park Plaza. Easy to find and on thr iver. We strolled the river nightly and were within walking disatnce to the Eye, Buckingham Palace and the rest. The rooms were very clean, and the guest services were very helpful. Good staff and friendly room service. I will stay here again. We could see Big Ben, the parliment building and several other landmarks from our hotel room. Great view at a great price.

This hotel is really a great place to stay in London. Is walking distance from a lot of historic places like Big Ben and Westminster Abbey. Is clean, modern and the staff was really friendly.
The breakfast is complete and has a good quality. The room was big and clean. They offer internet wi-fi in the price, which was really good.
My husband did not believe the price we paid for the stay; thought it was much more expensive.
I recommend this hotel for your next visit to London!

I stayed at this hotel in August 2011 as part of a tour group. While the front desk seemed friendly enough and were courteous, the room was small and not very spacious. My daughter and I found the beds to be extremely uncomfortable and far from what we're used to considering the price. Beware of bugs people! In your beds and elsewhere! The service overall was just average and I found the concierge on duty to be rude and short when asking him for assistance.

While he conveniently helped other guests, he was quite dismissive when I asked for information about a tour. When I brought this to the attention of the manager, he stated he'd take care of the situation and I never heard back from him about the problem or assistance with the tour! This hotel is at best maybe a 3-star by U.S. standards. The breakfast is average. I never plan to go back and suggest you look elsewhere if you want an upscale hotel and better treatment!