Guppy, Skyhawk (and others), I appreciate your comments, but at my age and with a long-term leg disability, I am not now going to go into any physical training in learning to jump. With a less than 1% chance of having to use one in a long gliding career, most of which is now behind me, I shall take my chance along with the small numbers of glider pilots who have actually had to jump, and hope I will cope as well as they did if it comes to it.
By coincidence, there is a very active correspondence (98 posts so far) on a gliding website at present. Adherents of square chutes are telling everyone how good they are, people who have actually jumped with round chutes are saying they worked okay for them.
As emergency chutes are typically lifed for 15 to 20 years, replacement purchases are pretty infrequent.
Chris N.