Specifically, Release 6 (which includes build 15.2.6) introduced several workflow-critical updates:
Unlike older versions that edited line-by-line, version 15 allows text to reflow naturally within blocks, similar to a word processor. ABBYY FineReader PDF 15.2.6
The "15" series brought significant shifts in how users interact with documents: Specifically, Release 6 (which includes build 15
Document comparison was expanded to include Greek and Chinese . Performance & User Sentiment Upgrade to the Newest Version - ABBYY FineReader PDF number of pages
Added the ability to split large PDFs by file size, number of pages, or bookmarks.