I'm a filthy casual that spends money of parts of the game that I like,. for example I have 4 premium houses, and have bought cosmetic house items in the Store.
As far as gameplay goes, I HATE slug fests and grinding, so I stop at the Dead City in Minas Morgul and head straight to Langflood which is a lot easier and has storylines, like the historian from Rohan.
With Epic Quest lines, I skip Vol 1 and 2 and start at 3, for the reason that I hate slug fests and going back and forth. I'm in this game for story lines, not hack and slash.
With the new updates on upgrading imdubed LIs, I'm pretty much done at max level. I enjoyed going to the South Gate at MT to farm scrolls because it was relaxing, but with the new rules, it's no fun.
So to make a short answer, I play and enjoy up to where having to grind imbuded LIs is necessary and I avoid any part of the game after that. Seriously, SSG screwed the hooch on that.
"Grandchildren are God's reward for not killing your children when you wanted to."