Play, die, laugh, learn.
To start, "Bravery Bonus" no longer requires
consecutive runs on Hard or Elite - any first run enjoys the biggest boost. So right out of the gate, there's that, even if you're only doing Hard every other quest.
Any Reaper difficulty gives a nice XP bonus - R1 or R10 is the same bonus, so many choose R1 for faster XP. Reapers themselves are a new monster to learn to deal with - they can spawn anywhere with other mobs, so are always a possibility. The 4 basic types (others appear w/ higher R levels, R5+) each have their own quirks, and best tactics to beat/avoid them:
(You'll also gain Reaper XP (RXP) - slowly, but it will come. There are 3 trees - Melee/Ranged, Caster, and Defense. If you're a button-pusher, put 4 points into the boost to your offense first, then fill in the Defensive tree to maximize hit points and survivability, and to get a 3rd use of that boost. Tiers are level-gated - you can spread a little around (2 more points in the 3rd tree for a 4th use of that boost), but it's slow, so "defense" is pro'ly the best bet during a first life. You might get a total of 10-15 points by TR, depending.
o
https://ddowiki.com/page/Reaper_enhancements)
Similarly but to a far lesser extent with Champions, which are exactly that - mobs on steroids. MucH tougher, and coming in a wide variety (20! - which are labeled if you have overhead labels turned on). Some are obvious - Soul of Ice does additional Cold damage and takes extra damage from flame attacks, and a Stone Guard spews DR/PRR/MRR, but you never know what cards a Mark of Chaos is holding. Many (~25-75%, depending) have True Sight, which translates to a big nerf for Invisibility in Elite mode.
As you may see, in general it's
much easier to find experience now, so if your build is solid, or you're just with a solid group, it's simply much faster to level. And from now to Monday morning some time it's a "Buddy Bonus Weekend", +5% for every additional member of a party, so a potential +25% on top of the usual. Win!