To speak directly to the concerns you seem to have on this subject:

"...when I say 'sealed' I meant cartridge type hubs. So for touring, when carrying a load, would cartridge hubs or cup and cone hubs be better?"

It would depend, in part, on the exact type of cartridge bearings. If you are looking for maximized mean time between failures, or maximal maintenance intervals, the higher quality cartridge bearings are probably the best way to go. Phil Wood sells extra-heavy-duty bearings, for those who prefer them.

If you are looking for the most trouble-free servicing, as well as the most trouble-free operation, most Phil Wood hubs are extremely easy to service -- much easier than non-cartridge cup and cone bearings.

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To make what could be a very long response shorter: A lot depends on you and the criteria you have. If economy is a factor, that influences the recommendation. If you have mechanical skills and do not mind overhauling cup and cone bearings, that also influences things. If your overriding priority is reliability couple with serviceability, that will also influence the recommendation outcome, or the evaluation of the available options.

In sum, It depends to a large extent on your evaluation criteria.