Pielorinho said:
D+1, I think you can safely assume that anyone who's read thus far is unworried about spoilers

.
You can safely assume whatever you like right up until somebody complains.

But I was just playing around a bit anyway, trying out the spoiler code. I'd seen it used before but never had any need to use it.
As I said before, although this encounter looked tough on paper, in play it was a cakewalk for my PCs:
And that is The Key - you're providing anecdotal evidence. What happens when the party doesn't HAVE 3D combat capabilities as yours apparantly did? Or simply doesn't have them ready because the encounter along with the preceding one were
intended to catch them off guard? Or if, as DWARF mentions was the case, the party are not heavily combat oriented in the first place (especially since the adventure is as much investigation and mystery-solving as it is bloodletting)? Or the DM is operating under the reasonable understanding that the module has proceeded well so far and doesn't see the encounter's high lethality potential?
Speaker is not without it's problems, but it's a useful module, easy to plug into an ongoing campaign, and mostly plays out well. It's just this one encounter that was, IMO, quite stupidly designed. The aims of the encounter can be handled far better with a much lower EL and without the, "There's definitely a small chance the PC's will survive," approach to its design.
When I ran it, I recall that I adjusted the EL down by removing the two rog5/asn1 assassins and then ran it as being a bit of a rushed, disorganized assassination attempt making it actually an easier fight than I had intended. But then the PC's faced the missing two assassins later in a seperate attack and that had the added bonus of making the PC's actually paranoid about being assassinated. They stayed awake and locked in a house for the next day and a half.

The purpose of the ambush was thusly accomplished without having run an encounter where the
intended goal of the PC's is merely to escape alive. A goal they have to figure out
after they're already knee-deep in the fight which is otherwise intended to kill them handily.