It was perfect. Absolutely perfect. A tribute, tip-of-the-hat, homage to days gone by. It was subtle, funny, sweet, and had some quick biting commentary ("Decorative vegetables" and the Master's "beard") on both eras. Peter Davison is still, quite, The Doctor. And the last part was quite simply David Tennant and Steven Moffat paying tribute to The Doctor they grew up with.

Just perfect.