Disclaimer
This is an early review for Soda and we are still testing her so the review and rating might get updated in the next few days.
Soda skills

Skill 1 - Spotless Chair
■ Activates after 180 normal attack(s). Affects self.
Maid Spirit: Increase Max HP by 13%, stacks up to 5 time(s) and lasts for 10 sec.
This skill allows Soda to drastically increase her Max HP and at the same time it heals her (at least until you reach max stacks - then you have to wait for the buff to drop to get the healing again). Sadly, it takes a while to do 180 normal attacks and she needs to do it 5 times to get to max stacks. This combined with the long ramp-up time the LMG has makes it quite hard to do.
Furthermore, during boss fights despite the pretty long 10 sec timer on the buff, you will often lose all stacks (since you need to hide behind covers etc). And getting them back takes a while. This makes Soda way less forgiving than Pepper who doesn't have such issues with keeping her stacks up.
Skill 2 - Squeaky Clean Floor
Cooldown - 12 seconds.
■ Affects all allies.
Restore HP equal to 3.23% of the caster's Max HP.
■ Actuivates when Maid Spirit is fully stacked. Affects all allies.
Restore HP equal to 12.71% of the caster's Max HP.
The skill allows Soda to heal the whole team, but sadly if her S1 skill isn't stacked, the heal is really really low. But even if you managed to stack it up fully and keep it that way, our tests showed that Soda's healing output is below that of Pepper, Rapunzel, and even Emma or Helm.
Burst Skill - Spring Cleaning
Cooldown - 20 seconds
■ Affects 2 enemy units randomly.
Deals 321.8% of ATK as damage.
Stun for 1 sec.
■ Affects all allies with Fire element.
Stack count of buffs ▲ 1.
Soda's Burst skill attacks two enemies and stuns them while at the same time increasing the stack count of buffs for Fire allies.
For PVE, the two-target limit is really bad and hard to make use of, but in PVP this means that nearly half of the enemy team will get stunned and if you use Privaty in the same team as Soda, this will allow you to abuse her on-stun additional damage.
First impressions
Soda is another Burst I Healer available to the players, but sadly she's the weakest among the bunch - Rapunzel and Pepper are easier to use and heal more and even Emma who suffers from the same issues as Soda (so being LMG wielder) performs better in the role.
Still, Soda potentially can be really strong when paired with Sin since Soda has the highest amount of HP in the game (once at max stacks) and if Sin duplicates part of it, she will get a massive heal/cushion that allows her to survive the Taunt. The combination is currently being tried by some Chinese players and from the reports we saw, it allows Sin to be the first Taunter in the game that can actually Taunt the whole screen and survive.
Soda and Sin combination has the potential to work really well in both PVP and PVE, but we need to test it further. Sadly, Soda alone isn't worth pulling, but if you have the patience and you've chosen Sin in the Liberation mode then she might actually prove really good.
Ratings
The ratings below don't take the Soda and Sin combo into account as we need to properly test it first.
Story - B in early and A in mid/late game. Sadly, compared to other Healers it takes Soda way too long to reach the healing numbers other Healers output.
Bosses - A in both solo Bosses and Bosses with adds. While other Healers are better, she could shine in Union Raid as there you need to use 3 teams.
PVP - B. Her low energy generation and reliance on stacks make her below average in PVP.
Should you pull?
At the moment she isn't worth it, but once the banner ends adding her to your wishlist might be a good idea since in the future she might be a great pair to Sin.