I see you took the 'Yay' option, then! I've dived with a thigh-pocket for years, and wouldn't be without it - I keep slates, spare mask, spare fin-strap, trauma shears and allsorts in mine.
One thing you might want to consider is that retrieving items from the pocket can sometimes be a two-handed task... and an SMB can be a 'need it in a hurry' item. Peter_C is spot-on with his advice to clip everything to a bungee fixed inside the pocket - that way, if hurriedly pulling out your SMB pulls other items out of the pocket, at least they're still attached!
FWIW, my solution was to keep my 'maintenance items' in the pocket (which, as it isn't glued to me, can be handed off to whoever needs it...) and have my SMB and spool hung in a side-opening pouch below my cylinder/BC so that I can simply reach back for it with one hand if I'm in a hurry.
I guess it really depends on how much stuff you need to carry on your dives... a thigh-pocket is a very useful bit of kit that I personally recommend, but do be sure that you can actually get at what you need, when you need it!