Went to Sandown in a TB20 nearly 3 weeks ago. Clearing the runway onto the taxiway was like taxiing through wet concrete. Eventually gave up and shut down as I have seen others ground the prop in similar circumstances. We were therefore blocking the runway, but only for about 20 minutes. I am not sure if this is the incident reported above. The ground actually felt quite firm underfoot but was obviously soft enough for the aircraft to get bogged, and there was no visible indication that the ground was soft in that area. The friendly and helpful fire crew towed us onto the taxiway using their 'mule.'
I would certainly not say that Sandown is the smoothest grass airfield; in fact on that day the runway felt like one of the roughest I have used!
Taxi was £5 each way into the town and back.
I have nothing against Sandown and think it is a very pleasant grass field but maybe Bembridge is more suitable for an aircraft like the Bonanza. The wind at Bembridge was exceeding crosswind limits on the day above otherwise that is where I would have been!