Hi RobMSport & Fellow Alfistas.
I've only just found this thread and it's sort of music to my ears. A short background before the glow-plug bit. 6k miles after buying a 28k mile, 59 plate 2.4, 210 Brera a year ago, the turbo oil seal failed, causing an engine run-away. That was quite 'exciting' as I was half way round a round-about at the time - 6500 unwelcome revs and quite tasty, unintended acceleration. I managed to stall it 30 seconds later (after getting out of the traffic, with massive smoke screen behind me). After Alfa UK's complete lack of interest a good mate properly rebuilt it for me (pistons & rods out for checking, new rings, head skim, new valve guide seals, new turbo, new injectors etc etc. There's more but I won't go on). The glow plug warning was coming on, so I checked them & 3 of the 5 were O/C. I replaced all 5, but noticed the new ones were about 5mm shorter than the old ones. But they were the ones that several factors had spec'd for the car.
So I was a bit miffed when it started smoking heavily on cold starts (it still runs great other than that). Your thread has put my mind at rest that its not something more serious - after experiencing a run-away, any minor engine issue causes grief.
So, in common with RobMSport I'm checking whether a late 2009 2.4 210 (Brera in my case) should have the longer Beru GN069 plugs? From my experience above, I'm pretty sure it should?