SS, chrome moly clean the same. Chrome MIGHT be a little easier, but I don't notice any difference.
SS is more accurate... for target bull barrels. For the types of barrels used for general shooting ("govt", M4, HBAR, A2, etc) there is just not a noticable difference between the three.
I like SS for its corrosion resistance, and chome lined for the same reason. But I have several rifles with plain chrome moly barrels, and these shoot well, too.
I doubt I will wear out any of these, as I don't fire full auto. It is heat that damages barrels the most.
A 300 rnd battle pack, fired in 30-45 minutes would not likely harm a barrel. It would be quite hot, but not really enough to damage the barrel. Dump ten 30 rnd mags at full auto, changing mags as quickly as possible, and that barrel is trashed.
Remember, the MAIN reason for chrome lining was CORROSION resistance in rifles used in the very high humidity and rain of the jungles of southeast Asia when the M16 was introduced to our military.
If you want a good quality SS barrel, the Olympic Arms heavy barrels are excellent. With the right loads, these barrels can shoot 1/4 moa. I suggest just buying the whole upper already assembled. The upper you want, with flattop, 20" ultramatch barrel, and free float tube, is their K6 for $630.00.