Actually, the cold temps/CO2 thing were something I was wondering about. Pulled a taste yesterday, yep, if it was a British beer it'd almost be overcarbed.
Yeah, at first it feels drastically different from ales, but once you get your head wrapped around how it behaves at certain temps it's easy to redefine "normal" behavior.
The following morning things were rocking, both beers seem to be fine.
One of these beers smells like an egg though, lots of sulfur. What really contributes to this? Grist? Yeast? I do have copper in my plate chiller, so that "side" of it has been taken care of.
Yeasts used were WLP835 Lager X and Wyeast 2001 Urquell Lager. Sniffing airlocks makes me think the 835 is the sulfur bomb culprit.
I haven't used those particular yeasts, but some are more prone to throw sulfur than others (and lager yeasts generally have more of a reputation for this than ale yeasts).
The good news is most of that stuff is quite volatile and blows off quickly with the fermentation.
In my experience I've found that as I "get to know" a particular yeast strain and how it will perform in my system, I can minimize sulfur with higher pitching rates and making sure that I pitch as close to fermentation temp as possible (preferring to pitch 1 degree below and rise than to pitch 1 degree above and drop). That level of obsession may not be necessary or beneficial -- just something I've noticed.