The Park Lane is pretty weak in comparison to the other SPG options, as well as competitive options.

The Classic Rooms are to be avoided at all costs as many of these are absolutely dreadful and not worth a fraction of the price you'd have to pay. The Executive Rooms on the other hand are all refurbished and are much nicer rooms to stay in, with some rooms having very decent views.

The hotel can also be rather generous with upgrades for Platinums. I've mainly had suites as upgrades in the past, but have declined studio suite upgrades when offered and asked for Executive Rooms as these tend to be consistently decent, as opposed to the Studio Suites which can be old and nasty.

If you can secure an Executive Room, then it isn't a bad option at all. It might be worth calling to see if the hotel will do an Exec Room for the dates that you wish to redeem points on. Failing that, they often send an offer to upgrade a Classic Room to an Executive Room in advance. From memory the cost is £30 per night and it is worth every penny in comparison.