Sunny is not too bad with him actually, she just gives him daggers whilst he walks past! She's very tolerant, and he only stays for a couple of hours then I let him back out to go home across the road.
Originally Cat's Protection thought he was only around 5 years old, but having spent time with him myself and also Linda agrees we think he must be senior, around 13/14 years old I would say, he's very placid, and quiet, he sits and rocks back and forth and falls asleep standing up, exactly like our family cat Doris does and she's elderly, 17 years old.
I just get this elderly vibe from him, he's extremely sedate, and not at all active in his demeanour, which makes me think he is definately a senior kittizen. He only wants to curl up and sleep, and purrs very serenely, he doesn't demand attention, but appreciates it, like as if that's all he wants out of life.

Incidently, I don't think I said this when I've talked about Jack's passing, when I asked the vet about Jack when it was time for him to go to the bridge, regarding his age, he said that he thought Jack was certainly elderly around 16 years old. We thought by his age given when we adopted that he was only around 12, but the vet said he had all the signs of being a geriatric cat, and in particular the way his right eye had changed colour and also of course his hyperthyroidism.