Funny thing with 930's they will not cycle the lighter birdshot/target loads *until* you run a box of full power 3" magnum slugs through them.
I assume this is for breaking in the action and to loosen the parts up abit .
After encountering the same FTE issue with my 930 SPX, 1 box of magnum slugs and it runs everything. I used to use the cheap Wally Mart #4 without issues, but I may switch over to #7.5's after experiencing how much better they perform.
930 vs. 1187, the 930 uses a forged aluminum receiver and as a result, is MUCH lighter than the 1187. I am noticeably faster on target with the 930 vs my 590A1 SPX (bad comparo I know, but it's what I have in my armory

) That may or may not matter to you.
The 1187 has alot more mods, parts, and gizmos available for it. The only parts available so far for the 930 are through Simon at S&J Hardware.
Personally, I do not like the way the 1187 functions (you will find every manufacturer makes their autoloading shottys different) The 930 has a button for bolt release and the same button will also unload the magazine tube when you press the elevator up. Press and hold elevator up, one press of the button releases 1 shotshell from the magazine tube (every manufacturer should be doing this) But this just boils down to personal preference.
On the matter of the SPX quality issues, yes, there are documented cases where the front sight tower was off a few degrees to ALOT of degrees and the receiver rail being torqued down to much, but you'll never be able to get an SPX in Canada anymore due to it being a 7 round magazine tube (all they have to do is take the +2 extension off???)
The 930 Tactical is close to the SPX minus the ghost rings rear sights, fibre Optic front sight tower, and +2 magazine tube extension.