I became the proud owner of a 13 year old tibetan spaniel 2 weeks ago.
She is the sweetest little dog ever, she is so funny and playful.
I've never had a tibbie until now, but if they are all like Pepe I'd highly recommend them.
She loves people, though I have read that they tend to ignore strangers, Pepe obviously being the exception to the rule.
They are extremely alert, thats what they were bred for but Pepe wakes up at the slightest noise, and often barks, waking me up in the process(only because she sleeps in my bedroom), that really is a desirable thing I guess, and may prove useful one day.
I'm not aware of major health problems, though I do know that they are more prone to problems with anaesthesia.
I've found her to be the perfect dog, small, very portable,. loves travelling on car and bus journeys, nothing seems to phase her , she went to the groomers for the first time the other day and behaved perfectly, wasn't at all frightened.