Merlin Banner or New Year Banner

It goes down to the banner where there is the servant you want rather than the banner where there is the servant you need.

In my perspective, I will still go for Merlin. He goes well with everyone since he is a support and the servants in the 2019 pickup are mostly damage dealers that I have plenty. As far as gameplay is concerned, top tier servants in that pickup are only Gilgamesh, Scathach and Musashi. And note that if you pick a banner that has all of the featured servant, chances of getting what you want is almost negligible, say 0.01%. At least, the SSR drop rate is still 1%.

So pick what your roster need most, a support servant or a damage dealer servant. Good luck in your future rolls.

First off people who dont use Merlin are probably whales or that ultra Ex rank Luck guy that rolls 5 stars with only tickets and one 10 pull. Or they just want to roll for their favorite Nasuverse Characters. Waver is in a tier of his own because he is in a game that is centered around buffs and more buffs in order to deal the most damage. So if you had a better version of waver who is already S tier what do call that guy? SS? Broken? Buster Memes? He is called memelin for a reason.
The only reason not to roll Merlin are these 2 main ones
1. You dont wanna trivalize harder content by just brute forcing them despite the gimmicks they offer by challenging yourself to create or figure ways to approach the CHALLENGE quests or raids without firing up google to search for a walkthrough made by JP trailblazers
2. You just dont like Merlin and his character more than your favorite servants so you save for them instead. This is larger percentage of people most of time.

If you wanna min max and get the "best" servant in the game. Since doing big damage is satisfying in its own way by all means roll for Merlin and collect 5,000 FP per day. The cool thing about FGO for me is different for others and that just means FGO is a good game

Merlin is the strongest support servant in the game period. he is overpowered with the Hero Creation skills, in fact he was so strong that he should have been nerfed out of sheer broken-ness but it was not possible due to, apparently, some Japanese gacha law.

Objectively speaking Merlin is probably the better servant as he can support literally anything you want whenever you want.

However this is Fate/Grand Order, THE waifu game where strength is irrelevant as long as you just get the servants you love, even Mata Hari or in my case Hans. I definetly will roll for Merlin but because of husbando reasons. But if I was you I would just roll for a banner with your waifu instead.

Honestly, multi-rate up banners are usually considered worse than single rate-up banners. Having more 5* servants on rate-up doesn't increase your chances of pulling a 5*, it only REDUCES your chances of pulling any individual 5*. As for having the CEs on rate-up too, that's true. The only reason to roll a multi rate-up banner is if you are only in it for the CEs and/or don't care which rate-up servant you get.