Well I'm not much help because I have one of each
What you need to work out is what you want from a hamster. Do you want the fun of watching a robo zoom around or do you want to be able to handle a hamster & interact a lot more? If it's the latter, then I'd say Syrian. If you've not Pwnef hamsters before them a Syrian can be easier. Where you live, can you get rat sized toys & a large wheel that a Syrian will need? A lot of stuff sold for hamsters is only suitable for dwarf species.