Agreed. I actually tested it, was similarly underwhelmed, and reloaded a previous save and spent the perk elsewhere. The top perk seems underwhelming too, although I haven't tested it. But a small chance to paralyze something that is going to die in a few more seconds (1-2 more shots) isn't worth it imo.
Something must be wrong with you guys or with me. I move at normal speed (or very close to it) with my bow drawn after taking that perk.
I think the top level perk (chance to paralyze) would be very useful for a casual player, one who doesn't min/max or worry about grabbing the best gear. I was looking forward to it for a long time, imagining how easy it would be to kite tough enemies with the stagger perk, paralyze perk, and maybe even a paralyze enchant on my bow. Enemies would barely even be able to move. However, now that I've made a Daedric bow and improved it with 165% blacksmithing, and equipped items that give me +80% damage with bows, most things die far too quickly to worry about kiting (killed a mammoth in 2 shots yesterday). Still, its hardly worthless, especially for people who don't add like 300% damage to their bows.