User blog comment:HubToo/Massive structures now!/@comment-25612015-20160117221501/@comment-25612015-20160117230504

It depends on the tool making the schematic.

I can confirm loss of some info with WorldEdit (at least with the 5.6.3 version I use on the server - the last one compatible with Minecraft 1.7.10 as far as I know): it doesn't know about LOTR blocks (peculiarly their data values), and thus has issues with complex ones (stairs, 2 blocks high plants, etc.).

I have had better results with Schematica, though its schematic files are not completely compatible with WorldEdit ones.