Turkey crown cooking time?

[Antaresisastar]

I have bought a turkey crown for the first time this year, it weighs 4.5 kg. there are only 6 of us for dinner so I know we will have plenty and lots of meat left over (which is good).
I am used to cooking a whole bird so I googled cooking times. Hugh Fearnley-Whittingstall seems to think it will cook in 85 mins, Waitrose say 3 hours 45 mins, other websites 3 hrs, such a difference. I have a meat thermometer and am happy to let the bird rest for an hour, how do I end up with juicy lovely turkey that won't kill us.
If you have cooked a crown before, and it was lovely, please tell me how long it was in the oven. Thank you.

I too have a crown for the first time and have no idea how to cook it, so will be watching with interest.

Calculate 20 mins per 450g and add another 20 - 25 mins. For 4.5kg I make that 3 hour 40 mins minimum. Check after this time and return to the oven if it needs a little extra time.

My personal method for roasting is to get the oven very hot to begin with... 220C or Gas 7.... roast in foil at this temperature for the first 30 minutes and then turn down to 170C or Gas 3 for the rest of the time barring the last 30 minutes. Peel back the foil, baste, cover with bacon slices and turn up the heat to 200C or Gas 6 until crisped. Once cooked, allow to rest under foil and tea towels for at least 30 minutes before carving.

Do butterflys cook in a similar times to crowns or even quicker due to no bones?