i am considering a project like this too, for simplicity's sake on a folding bike..
they are very nicely made hubs, if a bit heavy.. not sure what is meant by 'sloppy action'..
they shift very positively as there is only one gear change possible at any given time..
perhaps you mean the pawls do not engage instantly ?

like other internal gear hubs they are pretty simple to service and there is little to go wrong..
the one part that does sometimes break (index spring) is not completely unattainable and at times available for around $10-$20.. i think via bikes in philly (senditnow) has these in stock... it is also possible to easily repair this spring and, as they are not a part requiring any precision, probably simple enough to fashion from scratch...

i think the main disadvantage of these hubs is the inability to change sprockets.. you must use the official gear which always seems to be 18T.. not really a problem with large wheels..

the most useful ratios are probably found in the red and yellow band hubs.. 1:1 and 1:0.66 low gear
the blue band has an overdrive and is seen for sale less frequently.. the blue and yellow band hubs are later versions and have the improved shoe-style brake...

o, and message me if you'd like as i have a nice yellow band for sale/trade !