I stayed at both in June. Neither is dazzling, neither will give you the feeling of being adorned with a lot of diamond benefits, but you'll get your 'entitlement'. The Hilton is definitely older ... and feels like it. Its main upside is a really good commercial gym on site that you can access - if that happens to appeal.

The Doubletree has small rooms and the characteristically small bathrooms of ex-Mint hotels. But it is a clean and decent hotel which I preferred to the Hilton. So, that's where I'd recommend.