Waldorf Largo soft synth. Yep, that's the sweet hard-cover manual they include in the box. Installation was a breeze - I use it as an audiounit in Logic. I use a dongle for the license, but no problem for me because I regularly use the synchrosoft key anyway, and I'm familiar with their setup. Used the code from the box to register, and they send the e-license to the key. (Update: hardware dongle is NOT required. They offer a 'software e-licenser' as an alternative. )
Does it sound like the Blofeld? Yes, I think so. In fact, on most patches I think it's nearly identical, assuming you're using the same ingredients. The Blofeld has the PPG filter emulation, while the Largo doesn't. Instead, the Largo got a nice useful EQ and also sub-oscillators, not found (if I remember correctly) on the Blofeld. I think the basic architecture is the same in terms of number of oscillators, dual filter setup, FM, etc. The Blofeld will certainly still hold its own as a standalone synth. It's more hands-on and can also get the Sample Wave option. I don't think Largo's getting that one.
Just the way my studio is setup, I run all my Logic sessions at 96k. Largo held up just fine at 32 voices on my Mac Pro. You could definitely see it eating up most of 1 whole CPU bar, but there were no audio glitches, drop outs, or buzz (unless intentional!) There were, however, scary loud moments if I did too much filter FM with high resonance and forgot to turn down the volume. I haven't tried to see if this is better at 44.1k yet.
It's great that Largo has 4 large layer buttons laid out right in front. It's super simple to copy settings from one layer to the other. In one of the demo clips, you can hear how I used just a simple sine staccato sound, but then spread it over 4 layers, each with a different arpeggio and delay setting! Of course, the old "layer the same patch but one octave higher" trick is also easy to achieve.
I don't really love the effects too much, but the delay is alright I guess. That's pretty much the only negative from me about Largo. Plenty of wicked presets are already loaded in, so no worries for the inexperienced. I can see myself actually spending the time to program patches, because the end result is worth it.