SA gears were never considered strong enough for enthusiastic use.
I wasn't riding at the time, but I imagine the various records that were set with Sturmey gears must've required a fair degree of exertion:http://www.sturmey-archerheritage.com/i ... ic-439.jpghttp://www.sturmey-archerheritage.com/i ... ic-539.jpg
There's a difference between a single record-breaking ride and a lifetime (or even a season) of grind, of course, but there are enough of these old hubs still going strong to make that assessment look a little uncharitable. I've put plenty of miles on Sturmey products over the years. If I'm not as strong as I was, I'm still just as enthusiastic.
Wish I could remember if the shells are the same, some alloy shells the LH end plate was virtually impossible to remove. Keep the alloy, the flanges are thicker, so less likely to break spokes.
certain the shells are interchangeable - assuming an older AW with a threaded ball-cup, of course.
On the other hand, I generally prefer the steel shells to the older alloy models. If the alloy flanges are thicker there's very little in it, and I'd sooner break a spoke than crack a flange.
While we're here, I'll post links to Tony Hadland's excellent site. He's long been the best place to go for detailed SA information on the web. He's got pdf files of nearly every model, plus extracts from the post-war master catalogue, gear charts and dimensioned drawings of many components:
There's also a wealth of information in the Sturmey Heritage site, but you have to dig for it:
http://www.sturmey-archerheritage.com/i ... tail&id=58
Calmes dans le demi-jour
Que les branches hautes font,
Pénétrons bien notre amour
De ce silence profond.