I bought the BSS 12 ga. Sporter 28" new in 1985 for $550, about the same time my brother bought a 12 ga. 23 with 25.5" barrels for $950. Prices for both were about the same amount below listed retail. At the time the 23's choke tubes protruded half an inch beyond the barrels for 26" total length. The 23 was half a pound lighter at just over 7 lbs. -- only an ounce heavier than my 20 ga., and much nearer the light end of the 12 ga. spectrum than my BSS. I stopped using my BSS for birds after a couple seasons, but still like to shoot it for clays.
One significant difference between the 23 and the BSS: With the latter, there were only 2 models, Standard (PG/BT) and Sporter (str/SBT). That is, if you exclude the BSS Sidelock, which is a totally different gun. In contrast, there were a bunch of different versions of the 23, some lighter (as noted above) and some heavier (like the Heavy Duck). But the BSS in general was not a light gun. A 12ga with 30" barrels (available in the Standard configuration only I think, and not often seen) is the real heavyweight, but might make a nice sxs Sporting Clays gun, with choke tubes installed.
Never owned a 23 and can't recall for sure, but I think the trigger on those guns is inertia-operated. The BSS has a mechanical trigger, and for a ST on a gun that's not very expensive, it's a pretty good one. A lot of people think the 23 trigger leaves a good bit to be desired.
