Apologies for being a little late to the conversation on this. I used 34/70 for years for all my lagers. It is incredibly forgiving of fermentation temperature, and it is squeaky clean. So clean that I always felt that it was missing something - that faint sulfur note that I pick up in most European lagers. I also feel that it tends to mute hop expression a bit.
I tried S-189 and once I got it dialed in, I switched to using it for the majority of my lagers. It gives that hint of sulfur that I like, and I think it does a better job at accentuating hop character - spicy noble hops like Saaz in particular. One thing I've found is that it is not as forgiving as 34/70 with temperature. I pitch it at 40F, then set my chamber to 45F for the first 4-5 days before slowly ramping temps up.