Just want to chime in, as I play both gemstone and dragonrealms:

They are very similar, but gemstone is more a D&D styled, pen and paper, roll-the-dice and see the die rolls, deal x damage, have x hp... Dragonrealms of course has these numbers, but they are hidden under well written text.

Additionally, gemstone is level based, so, earn 50k xp, reach level 2, and you are now better at fighting, casting spells, picking locks, etc, whereas dragonrealms is skill based, so you train combat by being in combat, train magic by casting spells, train foraging by foraging, etc... It adds a sense of personalization to your characters, so not every 10th circle (level) warrior mage is the same in dragonrealms, whereas almost every 10th level warrior in gemstone will be about the same.

Furthermore, in each of these games, everything is determined by your class. There is no dual classing, and while you have some flexibility in your training options, a Ranger will always be a survival expert over a Trader.

Neither game offers much pvp.

Both offer a small amount of crafting, but the economy is mostly broken in both due to inflation.

I find them both to be heaps of fun and a nice break from the MMO I play (EvE). Also, the interface is very easy to conceal, and I often play while on downtime at work. Give them a go, you'll be surprised and the player base is small, but loyal and typically very kind.