if it was exclusively for weed, I'd go for the MFLB, as it is portable....takes a *little*while to get the hang of....but, as I said, it really doesn't do a good job of hash, charas etc....also doesn't work with dmt...
The Arizer you can use with a whip(tube for toking), or you can fill bags (a la Volcano), it works with (high quality)hash, and it works great with dmt...can fill bags or toke from the whip.....
yes, it's a couple of hundred qud, but in your case I think £70 on an MFLB would be pretty much wasted as it just not for your needs....also, the £70 WILL need additionasl costs, as the bateries that come with the MFLB are not powerful enough, and the charger not efficient enough, and you need a few batteries if you an all day toker.....so you prob end up spending nearer a hundred quid anyway.....
It's a fucking great device for weed though.