I just defeated the E4 round 1 on version 1.4 (e: 1.3? whichever one was before 2.0).
My team was:
Ferrothorn@Leftovers/Iron Barbs
Leech Seed
Stealth Rock
Power Whip
Iron Head
Rotom-W@Leftovers/Levitate
Hydro Pump
Volt Switch
Shadow Ball
Will-o'-Wisp
Blaziken@Blazikenite/Blaze
Bulk Up
Stone Edge
Flare Blitz
Hi Jump Kick
Latios@Soul Dew/Levitate
Calm Mind
Draco Meteor
Psychic
Ice Beam
Garchomp@Assault Vest/Rough Skin
Crunch
Dragon Claw
Earthquake
Stone Edge
Crobat@Nothing!/Inner Focus
Acrobatics
Thief
Cross Poison
Toxic
I'll be attempting Round 2 after the Delta Episode (and probably updating to the 679 or Leveled version, as leveling new team members takes an absolute age of running around rematching trainers). I wonder how different the E4 is from Round 1.
Since I've nominally completed the game, here's my review: It's excellent! Any and all problems I had with it were related to things that are completely fixed by the 679 build. I did end up spending the majority of my money on healing items, largely Max Potions, and holding a few Full Restores and Revives in reserve. I didn't end up using any Revives on the E4/Champion but they were very useful for earlier gym leaders or Ace Trainers when species availability was limited. Basically, the increase in cost on Revives and Full Restores completely succeeded in its goal, along with the easy availability of Sacred Ash reducing frustration and tedious running back to Pokemon Centers.
EV training, hunting for high IV wild Pokemon, and looking for the correct Nature didn't seem to matter much; two team members were fully EV trained and the others just naturally gained EVs throughout the game, and I couldn't really tell you that there was a dramatic difference in performance (since it seems that opponents mostly have perfect IVs and will outdo you anyway).
Great romhack all around! According to my Trainer Card I have 120 hours played at the start of the Delta Episode; I would estimate I played probably 90-100 hours of that time and left the 3DS open while doing something else for the rest of it. It also took just about a month of occasional play to enter the Hall of Fame for the first time (from March 15th to April 11th).
Question: I remember something about the first three players with to beat the E4 round two (with proof) replacing an NPC or something like that. Is that still on, and if so, does the battle style have to be set to Set or can it be left on Shift?