The Mossberg Shockwave is a sweet Home Defense option. I very nearly got one in 12 Gauge myself, but ultimately went with the Taurus Judge Magnum since I couldn't find a safe yet easily accessible way to store a Shockwave at my bedside.
A 20 Gauge model would be ideal for those who are recoil sensitive or otherwise have concerns about keeping the 12 Gauge Shockwave under control.
I just got mine out for it's maiden voyage last week. Had the tactical barrel on it and fired some 00 buck and some reduced recoil slugs. Ran great with manageable felt recoil. I put an additional shock absorbing bumper on the stock but I'm not crazy about the increased LOP. Looking forward to putting the field barrel on it in Spring and trying clays.
The Tactical/Field combo works well for all of mine shotgun needs/desires and was $220.00 net.
I have the 12 gauge. The birdshead grip is underrated as a recoil reducing mechanism. I am merely 155lbs and 5’ 8” but I don’t find the recoil uncontrollable or too much. Mine’s a bear gun with slugs and double aughts alternated for hiking/camping and has Aguila minishells for Home defense.
20 gauge should still be a great gun regardless.