I used them on my 69 Camaro and would highly recommend them. As previously mentioned they are extremely flexible which gives you a lot more options on how you route your A/C lines, you don't have to take them anywhere to have them crimped and they have a cleaner look.
On the downside there are not as many fittings offered and it does cost more, but it's worth the extra money.
I bought a kit off eBay. Do a search on "EATON E-Z Clip System". This kit included the crimper, cutter and enough cages and o-ring in various to make more hoses than most of of would make in a lifetime.
http://www.ebay.com/itm/E-Z-Clip-Sys...item2a3f1a7e08