I think "Pie Zoes" in a solid body guitar can do a very convincing tonal sibling of an acoustic with a piezo bridge. Sure there are many differences in the sound you can tell by looking at the guitar but just by listening it can be tough. Here's one example. I would go so far as to say even a Tele with normal strings and piezo saddles will sound like a piezoed steel string acoustic enough for my needs. If your goal is to sound like a piezo in an acoustic I feel the piezo in the saddle of a semi hollow will get you close enough that the difference is irrelevant to me.