In theory for simplicity, the compared batteries are exactly the same weight, that consisting of lead and other material in both batteries, however, even if they contain the exact same amount of lead, how and the way those plates are made up and assembled will reflect on the performance.
A very good demonstration relevant as to weight comparison for this, is to compare the equivalent Yuasa YB16-B wet cell similar in dimensions and weight from the YUSA Motorcycle Battery up-grade chart, it is mostly recognised that an AGM battery will out preform and perform longer than a conventional wet cell due to it construction & technology, however both are listed as the same weight, you could argue the semantics of weather the case is exactly the same etc, however as this is all very generalised I doubt if this makes much difference, they weigh the same, but the YuMicron has much lower performance.
Also their is a top rated battery for this application, which is the GYZ-20-HL this is heavier but does have larger plates and different grid design.
I will put reference material in links below, but would state I don't have a connection or necessarily believe YUAS/GS batteries are better than others, my preferred choice is actually the DEKA OEM, it is just YUASA are very good with and easy to access their material along with their learning academy.
YUASA UK
YUASA Vehicle Flip Book
Battery Construction YUASA Video
Battery Construction PDF