Faction fighting was probably the most amazing thing about Siege. I had a lot of issues with Siege due to CBDs and IBDs, but one thing that I will not deny is that Siege had the best faction fighting I was ever involved in.
GL factions don't really compare, but since both shards are completely different in terms or insurance etc it's hard to compare them. I'd say the biggest thing is the only faction that ever really seems to care about sigs is TB.
GL in general is pretty archer heavy, thus not as fun for players who enjoy a challenge. I'd guess that GL factions are currently archery based as well.
As far as tamers, the taming problem on GL is not near as bad as it is on Siege. There are only a few tamers that I can recall, and they are all fairly bad players. Nothing like Corwin of Amber on Siege.