Those are about the same question. Here goes:
The LA-6176 is built from algos of shipping plugins: The 610, the 1176 and LA2A. For those previously shipped plugins or collections of plugins, there are derivations within the code that provide the feature and circuit variations, and specific golden unit fits to give you the eras and flavors of the 1176 Collection, for example. The 6176 and LA-610MkII hardware units are certainly right in the family with the hardware 1176, LA2A and 610 hardware variations that came before, and we still ship all of these as hardware units. So similarly, there are some differences within the channel strip emulations as well. That means you will be able to put your 6176 or LA-610MkII hardware side by side with the plugin and get a great match (minor unit to unit variation notwithstanding).
To get a bit more specific:
- The 610-B in the LA-6176 plugin is based on the LA-610MkII hardware, which has about 6dB more total gain than the 6176
- The 610-B preamp in the LA-610MkII is the same as in the 2-610 and LA-610 silver units
- The LA-6176 adds 610 features over the UA 610-B plugin : 75Hz Cut, EQ bypass and dual Hi-Z Unison impedance (47k, 2.2M)
- The 1176 in the LA-6176 is based on the 1176 in the 6176 hardware
- The LA2A in the LA-6176 is based on the LA2A in the LA-610MkII hardware
But yes, the biggest benefit of the LA-6176 is you're getting both of our hardware channel strips in one plugin, really combining "UA's greatest hits" of analog designs in one "super strip" plugin. And is of course Unison enabled for Apollo.