Just played new Karma on EUW and I love her, they managed to fix the majority of her old problems while still keeping similar gameplay (gameplay, not kit) to her old counterpart.
Q: Still a highly spammable short ranged poke, but they got rid of the almost-melee-range problem.
W: Still used for CCing a running enemy except they fixed the problem of it not dealing damage to the target and it being a negligible CC in the past. The move speed buff part has moved to E so it's not completely lost.
E: Obviously still a shield. The movement speed upgrade is a really nice add-on, not necessary but still nice.
R: Having 1 mantra is BALANCED. People who think otherwise should really sit down and think about it for a sec, Q is already on a 3 sec CD with 40% CDR, imagine 2 mantra'd Qs on a team fight, 1 is already ridiculously strong, or imagine 2 mantra'd Es, again 1 is already ridiculously strong.
R+Q: They got rid of the weird "Do I use it for the damage or the heal?" problem (NO, it was unlikely that you'll be hitting and healing at the same time mid-team fight) and made it a purely high damage poke/nuke, pretty straightforward.
R+W: Still find this a little meh, but in skirmishes the 25% health heal can turn the tables, I like how they kept the "LOLOL U BROKE THROUGH MY SHIELD NOW I'M GOING TO HEAL MYSELF...AND THEN SHIELD MYSELF AGAIN WHEN YOU TAKE MY HEALED HEALTH DOWN AGAIN GG" gameplay that old Karma had.
R+E: Still similar role, Shield + damage, but the newly added huge utility buff to this skill is amazing, OP TBH. AoE Shield + Shureliya's + AoE damage over a wide targeted area on a single skill, for real? lol.