Apologies for the phone shot (FOH Atlus), but here are my party stats after like... 30-35 consecutive battles in the second dungeon. Other members have lost a bit of SP due to this being my first visit here, so obviously I've been checking weaknesses etc.
Having the SP regen accessory on your healer is just nuts. You can use physical skills with absolutely no care in the world, get a persona with a strong one and you'll likely smash through enemies without them ever getting a turn in. You could even pass the accessory around and replenish everyone's SP by doing an easy fight a couple of times (I've noticed the shadows are pretty much always the same enemy party).
I'm pretty close to having enough money for 2 more of these accessories, hell yeah I'm grinding the money for them. Gotta leave the dungeon next anyway.