I see this thread is a few months old so maybe this is old information, but I just asked X10 support about this. I asked if I order a LM465 today will it have "Softstart". The answer was Yes.
So I ordered one and I'll find out in a few days if it's true.
Greg
It looks like tech support is still clueless. I got my LM465 today and it does not appear to have SoftStart (On command does not ramp up, does not respond to the extended dim commands). The date code is 07137. Looks like I wasted my money since SoftStart was the only reason I bought it.
EDIT: I thought I was in luck when I got the order confirmation. The SKU was LM465
-S (I thought maybe the -S meant SoftStart) while the SKU on my previous order last year was LM465-HA. But the box looks the same as always, no -S.
Greg