For major Coptic-ians, you can just quietly smile knowingly.
But assuming you just got your Horners, you might want to download Horner's PDF (public domain of course).
Here's an easy location: http://www.archive.org/details/copticversionofn02hornuoft
This PDF combines Horner's Sahidic text, with critical apparatus, and then the english (the latter now in Logos).
If you have the Logos Sahidic collection but don't see critical apparatus, that's because the Logos Collection is an update from Horner but no critical apparatus.
And if you're really talented with the english language, you can try to figure out just what the Collection 'is':
From the Logos.com page:
"Why a New Edition?
The need for a new edition of the Sahidic New Testament has long been recognized. However, the most recent version available in print was George Horner’s now antiquated seven-volume edition, released from 1898 through 1905. Recognizing the lack of a readily available Sahidic NT, the Packard Humanities Institute created a computer database version. The PHI’s edition applied to Horner’s work the many manuscripts that came to light after 1905, updating that edition with newer material.
In many ways, the PHI version improved on Horner's edition. However, the PHI Sahidic NT was never meant to be a critical text. It contained a number of inconsistencies deriving from its methodology and narrow goal. Ultimately, the resulting work lacked the usability desired by most serious scholars.
The text featured in the Sahidic Coptic Collection is based upon the PHI version. However, its view to usability based on consistency greatly enhances the PHI edition. Using pattern-recognition and analysis software, the Sahidic Coptic Collection text makes literally thousands of changes to the PHI version. In addition to comparing PHI with its source documents, additional documents have been collated with a view to giving a better representation of the overall tradition of the Sahidic version. All this makes the Sahidic Coptic Collection the best option for those wanting a usable and consistent edition of the Sahidic New Testament."
