Big advantage of T5 or pa4x, you dont need the rest of the band....
If you believe that, then you missed the point of the post. A good bit of the 'magic' comes from the interaction between the musicians. (The experience of) Watching the 'love affair' between the bass player or the drummer and their instruments just can't be duplicated on ANY arranger. That's not to say that you can't have an enjoyable arranger performance; but you're talking 'apples and oranges' here. Live music is so much more 'organic' in that you're watching a shared social, musical, spiritual, experience rather than one guy playing 5-25% of a performance. The difference is that no matter how sophisticated the arranger, the bass player or drummer on the arranger track is NOT LISTENING TO YOU, so as a consequence, you're always playing to IT. Also, since the arranger doesn't take solos, you don't get the opportunity to practice creative 'comping'.
Sure, arrangers certainly have a place in the music scene but I don't think we should always be trying to compare them to live music. Like I said, apples and oranges.
chas