I use ionic filters. WHen they are spent, you clip one off, and clip the new one in. Takes 30 seconds.
I could get refillable resin bottles, but really whats the point.
By the time I've messed around emptying, rinsing out and then spooning resin into a bottle, I would probably have lost more cash in lost work time than I would have saved.
Also, I dont really want to have to faff about with resin, i like the convenience.
And as for being "crap with a capital C", well I never had any problems, they seem to last quite well. Water goes in one side and comes out the other, there's not much to go wrong surely?