Well, that’s Mark gleefully shining the Pigsignal into the clouds

WHY BE A MARCHER?
Having played this from both the “tanky battle medic/traditionalist Landskeeper” end and the “strange rural scholar from strange rural monastery” end, I can say this. It’s grounded, low-fantasy RP with a strong sense of community, and the chance to play characters outside the usual fantasy mould.
We don’t get the Hero’s Journey of the swineherd who discovers he’s secretly a prince. We have a narrative of collective badassery, where a ten thousand strong horde (warning, earwormy song) of swineherds, millers, bean farmers etc walked out on their wierd, idealistic landlords, armed themselves to the teeth, and invaded the neighbouring orcs to find a place to settle. We’re what happens when the L1 Commoners of every D&D campaign decide they’re going to put on the boots, grab some pointed sticks, and solve their own goblin problem today.
The Landskeeper brief is super interesting, as they take bits of Discworld Witch, bits of eccentric hedge wizard, cunning folk etc, and they make it into something new. A tradition that cares for the land as you’d care for a prize cow, but doesn’t venerate it religiously. They’re a great excuse to play a character with strong beliefs of putting the Marchers first and not looking at short-term goals. They’re very much professional meddlers, using magic (or hearth magic, or just Knowing Things) to grease the wheels of Marcher life. Go prod your nose into all Marcher stuff with “I’m Here to Help, Don’t You LIKE Tradition?” as your excuse. The magic style of the Marches is a great one if you like a performance that’s bold, simple and full of heart.
The Monasteries are one of my favourite briefs full stop, as they offer the chance to play in a group with a strong central religious theme, but with less pomp and ceremony than if you were to go Highborn (there’s totally a place for pomp, and it’s over there :D). They also mean you have an excuse to read into the absolutely amazing and often bonkers history of actual monasteries, their rules, and the way many of them kept bending those rules with wild abandon. We’re historically inspired but not historically accurate, which means you can get great deals on second-hand re-enactor kit, or gleefully rip off Cadfael, or get your pewter bling aesthetic on. It also means the costume is innately practical and comfortable, because the ideal is stuff that people actually did wear while working in a field.
In general, the Marcher theme is “family” and it’s great. Any given Marcher can have long running low-level feuds with everyone and their dog, but Paragons bloody help you if YOU openly pick on a Marcher and the five grumpy farmers they were grouching at all turn around and go THOU WOT, M8. You can get the literal and metaphorical brawling, and if you don’t want to be too cutthroat in your PVP dealings, it’s a pretty good place to be.
There’s not much that exemplifies the social feel more than the evenings in the Merricks’ Community Hall tent, and the singing the Marcher detachment off to the Battles. It’s a nation that’s quite easy to get in on the game for, and if you play combat characters, the comminity feel extends OC to lending weapons and armour, training people in fighting skills, etc. I think it’s a great springboard to fest larp, and although I want to work through the Nations on future PCs, I’ll keep coming back.