Yes. recently fitted one to mine. I had the separate gel seat and pillion before and "management" was complaining about the pillion!
I have not done any real long rides since but it is definately more comfortable and the support the backrest gives does make a difference. Adust it right and you can just lean back and cruise!
One point on the downside. You need to develope a new technique for getting off the bike. Getting on is fine as the backrest just folds forward as you throw your leg over. However, getting off requires you to either lift your leg somewhat higher than usual or hold the backrest down while you get off. I have opted for the first technique!