I sent my Zippo in for the free pipe conversion. It took exactly one week. I just love the Zippo action, but they are fussy to keep filled:
My Boswell, craggy-top plateau doesn't work well with the Zippo (too deep), so it gets the match.
I use the Black can of Zippo fluid, never tried Ronson, but the black can is much better than the old. To be honest, I can tell no "taste" difference between the match/Zippo or a butane.
You can also get a butane insert for the Zippo for about $10. I haven't tried one yet, but the Vector was recommended. For $10, I'll put it in one of my Zippo cases:
http://cgi.ebay.com/KGM-Vector-Butane-Flip-Top-PIPE-Lighter-Insert-/370362013468