My horses neighbour is by Jumbo! He is by no means pretty, but he has a wonderful temprement and attitude to life, and is incredibly talented. He used to be an international eventer (has been round Badminton etc!) but not does pure dressage to a very high level. He's a really sweet boy!
The eventing stallion Med Night Mahout by Jumbo stands alongside my boy at Cliveden, so I know him well. Very nice horse with very calm, kind, laid-back temperament. He is a real poppet. There are other horses on the yard by Jumbo as well - including an absolutely ginormous 18hh hunter. All have v nice temperaments.
I have met one Jumbo offspring - a stallion who has a fantastic temp. My friend worked with a fair few Jumbo offspring & she absolutely loved them . She said they did come in different shapes & sizes but all had good temps & could jump. Her all time favourite horse, who she said was phenomenal, was Britannia's brother Kingdom. I saw him go XC and he really jumped. She has nagged me for six years to use Jumbo and he is definitely on my list to use.