Both QB's have had success at different times, both have undeniable qualities and downside.
Casey, 04 league MVP (most deserved) has sputtered this season and one important quality needed in most sport that has been missing at times in his game IMO is steadyness and being under control.
While energy and enthusiasm is a prerequisite to success, it can also be the enemy if allowed to boil over as it has on occassion in his past few appearances.
Dancing out of the tunnel in the player intros for the last game, and who da man style celebrations early on when the Lions were meeting with some success is energy more profitably held in obeyance for his on field performances.
Many times when people have a tendency to get that "high" there's often a butterfly effect as when things don't work/go wrong/wheels leave the wagon they tend to get proportionatly as low, as was apparent when he was struggling than eventually pulled in favor of DD.
Speaking of DD...an unqualified success as QB, never won a Grey Cup game in which he was the starter (I'll stand corrected if I'm wrong) and while he was on fire to start the season, the point totals fell off sometime before the run met with it's demise in Edmonchuk.
Early on he tended to eat the ball rather than ground it when defences were storming him, this now seems to be resolved to some degree. That said he has shown he hasn't been able to demonstrate his elusiveness, and the past game was scarry to watch him on the bottom of the heap on four occassions (first time in after a concussion).
In DD's favor is his calm demeanor through success and adversity, and while Printers has the guns I like Dickenson for his leadership style.
In the interest of having readers stay awake...while there's more that can be discussed on the topic, my tenency is to go with DD to start, and unlike some here who believe he should go to the bitter end...that was tried last yrs. GC game and with all due respect to WB who "IS" the coach I still believe it was a mistake to effectively leave his QB twisting in the wind on that day.