More anarchic anura!
10 RHD (slaad HD progression is surprisingly ordered, it seems), the default fast healing and energy resistance package, DR/lawful (quite nice), +4 to +10 to all stats, Change Shape into any humanoid form, and a ton of SLAs, with the at-will ones including Identify, Invisibility, and Lightning Bolt, while the ones usable less often are Animate Objects and Power Word Stun, amongst others.
Summon Slaad is a bit more complicated than it's with earlier versions. Gray slaad can't summon others of their kind, but they can summon a green, a blue, or even two reds should they want to.
Once more the question is whether to assign +1 or +2, once more I'll go with +1.
In breaking with slaad rules (if that's not an oxymoron), these have a whopping fifteen RHD and are CE rather than CN. Other than that, these are basically gray slaadi with better stats, stronger natural attacks, bigger summons, more SLAs, and a 3/day stun rider on their natural weapons.
SLAs do include potentially juicy stuff, but we're talking about 15th-level characters here. +0 should be okay.
Do discuss, people.