Well, that maybe explained away as no one has spent the time trying to get those weight savings into LAMs, since it would mess up the balance of thing and you would have to spend a lot of time trying to account for the changes in balance when the LAM transformed.The engine sort of makes sense, because it would be awful hard to do the transforming without borking an XL engine. The rest? :FASA:
Speaking for myself, I don't expect LAMs any time soon. As you said, it costs way too much for a poorer product. They have a lot of other items that give a far better and faster return on investment. That won't last forever, but I'd expect sometime around the Clan invasion is when they'll start investing in LAMs again.