I have been using Logos Bible Software since 1996, when the product was installed by way of multiple floppy disks! Since that time, I have routinely upgraded my version of the software (I now have the latest, version 6) and added to the number of books available to me. This second aspect is one of the things that I like the most about Logos... all of the books in my Logos library (I have well over 1000, mostly carefully selected for what they can offer to my studies of the Bible) are fully indexed so that I can search for anything (scripture, topic, word, phrase, name, etc.) and can get a listing, within seconds, of every occurrence in every one of my books, and each and every scripture reference in every one of those books is linked to my favourite Bible (which, for me, just happens to be the NASB).
If you are in the UK (ideally not too far from Buckinghamshire!) and would like a demonstration of Logos to see if it will suit your purposes as a Bible study tool, get in touch and I'll see if I can help. Also, if you have Logos and would like training on the effective use of it from someone who has been using it since the last millennium, or you would like me to give a presentation about the software (demonstration or training) to a group, contact me.