Best use of Hilton HHonors points in London

I used to be watching this board frequently but have not since my last trip to London in 2011 so forgive me if this has been discussed recently.

I am planning to go to London next August for about 4 nights. I believe AXON awards are still in effect. Which property is the best bang for your points in terms of lounge, upgrade and location as a Diamond member? I have stayed at the Waldorf Hilton for past 3 trips and they have always been able to give us an upgrade to Executive level and even to a suite for an upcharge which was 90 GBP/night in 2011- arranged before arrival. Lounge was also decent.

I have been interested in Park Lane however heard there isn't much around there. I have a kid who sometimes needs quick snacks, etc. after the lounge may be closed. I'm not sure if the Conrad will be too expensive in terms of points. I had read great things about the Trafalgar years ago but at that time there was no Executive lounge. Did they ever open one?

I have stayed at Paddington and Metropole. Not really interested in staying there.

If you have any manager contact emails, please let me know.

thank you!