I recently returned from a tour around Ireland and suffered the same symptoms as you. I read through several of the threads on this forum and came to the conclusion that it is personal preference and how much you want to part with when ordering a replacement seat. I have gone for the Bagster comfort seat with gel inserts. You design the seat yourself, i.e, you choose the style, fabric, colour and trim based on your donated seat(s). The only problem is that you are left seatless/bikeless for 4 weeks whilst the seat is being made. See
here for details. Click on "Make my seat" above the Industry gif. I ordered mine from the Bagster shop in Abergele, North Wales (Tel: 01745 823333 ) and received 10% discount for having done the Bikesafe course. Cost is about £280 + donation seat.