(Apologies if I get any of the terminology wrong, I don't actually own the game, and while I have two friends who are really enthused about running it we haven't gotten together for a session yet.)
You don't have to. It's simple enough to just blindly figure out the result of the roll (more hammers than crossed swords? You succeeded. More birdies than skulls, or vice versa? You've got boons or banes). But the option's there.
But just the basics involves picking out the right set of dice from 6 different kinds, and then interpreting the results from 8 different symbols? (I think those numbers are correct?) It's not as bad as I had initially feared - being able to pair off most of the results so that you only have to deal with successes
or failures and banes
or boons certainly helps, but that's still pretty involved for a single die roll. In combat I know that handles both hit / miss and damage, but I can do the same thing in 4e by making an impromptu "die pool" out of my d20 and whatever I need for damage dice. I think the real question is going to be how much "action" a single die roll encompasses.
It seems to me that each die roll is meant to be more interesting / meaningful; if that's the case can we expect to be making fewer rolls overall? I'm also wondering about the odds: how likely is it for a typical roll to succeed? That's probably a lot more important in combat, where a miss means a longer fight and more rolling.
(One thing that kind of bothers me, if I've got this right, is that "reckless" dice apparently have several negative options not on normal / conservative dice, but still have the same total number of successes - they're just bunched up. Wouldn't that tend to make the reckless stance strictly worse than any other?)
But I just absolutely love the idea of every roll having a story built into it. It feels so marvelously holistic.
I'd be interested to know if there is (or can be) any story built in to the process of gathering / rolling the dice. My worry is that the extra complication on that end of the process is going to end up overshadowing any extra cool story bits.
One last thing - how does managing all of the cards work out in actual play? I'm thinking that the abstract positioning / range system will free up a bunch of table real-estate compared to 4e (and I think actually playing at / around a real table is going to be vital for WHFRP3; no lounging around the living room in comfy chairs / couches...), and the limit to how many active "talents" (?) a character has at once should help... I've just noticed that in 4e it's real easy to get a bunch of cards / chips with various ongoing effects / statuses and it becomes something of a nightmare to keep them all arranged / organized / on the table and actually apply them to appropriate rolls. I'm especially worried about conditions and critical wounds, since that's the kind of thing that's liable to end up getting missed, and going back and retroactively applying them is gonna kinda suck...