I've only had it for a few weeks. :S
They are completely different in personality.
My Syrian was the most cuddly, tame, hamster I have ever seen. His favourite thing to do was to fall asleep in my arms. He was just chilled out.
My Dwarf is very hyper, and much more fun to watch. She is awake in the day much more, poops a lot less. She lets me pick her up and she will sit on my lap and have a back rub.
I like them both for different reasons. Syrians are more inter-active, and draves are much more fun to watch, plus they poop less as they are much smaller. I have heard of dwarves being nippier than Syrians. There are four different kinds of dwarves, the campbells russian (most common, it's what I own), winter white russian (similar to campbells, less common, similar tempermant to syrians), chinese dwarf (very similar to mice), roborovskii (very hyper, and almost impossible to tame). Dwarves can be kept in groups, but expect fights to break out.
You just have to be patient with them and give them their peace ( ie. not bother them every two minutes).
10 Gallon Tank:
~Countless Pond Snails~1 Espe's Rasbora~1 Harlequin Rasbora~
5 and 5.5 Gallon Tanks:
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Many of my scaly friends from my original tank from 2011 have passed, except for two! I am in the process of re-doing my tank. :)