Either one works well. If you use crown caps, use the kind with oxygen absorbing liners & you might consider waxing as an added protective measure; it also lends some aesthetic value. Fliptops are easier, quicker, work just fine & have a certain aesthetic value of their own. I mostly use 1L fliptops cuz they're quicker & easier, though sometimes I still bottle in 12 oz bottles with crown caps for sampling purposes. That way I can have a good sample & not open a full liter. If you bottle, say, a 6pk of 12oz bottles out of a 6 gallon batch, you can really see/taste how your mead is progressing over the years.
Regards, GF.