Hey I also struggled deciding on what to play.
I’ll tell you what I got from my research. I want to give a big disclaimer that this is just based of what I read. I have only personally played Gunslinger and Blade Master.
Blademaster is basically the CC machine. If he gets close to someone then he will most likely do a lot of damage to whoever he CC. This makes him a big threat to people who are squishy and lack reliable escapes. For example Gunslinger only has 1 real from of escape and 1 cc breaker(at least to the level I played) If he already waste his long cc breaker and BM gets to him. The Gunslinger is most likely dead.
This doesn’t mean that he’s always strong against all squishy class. In fact, Swordmage is a BMs worst nightmare. That is because swordmage is actually the only “burst” class in this game. So there are a lot of situations like guildwars where a BM would get completely shut down by range. I think that is one of the down fall of being in melee in general though.
We also have gunslinger who has high single target dps which can shoot bms from far away. This is only a problem in big group fights.
You will see BM in a lot of leaderboards because he’s good in small skirmishes. 3v3 and 1v1 is where he will shine. In group fights you can still play smart and do well.
I heard that they are good in 3v3+
That is due to their extremely high burst
In this game you will come into certain situations where someone is low but you can’t finish them. Swordmage fixes that problem and does a pretty good job at securing kills. This is a good class if you enjoy seeing high damage and doing the most over a little period of time. So it’s all about positioning and how you use your displacement. Sword mage actually has more options of escape compare to gunslinger for example so it’s not that bad.
I believe range dps is more a threat to swordmage than melee but I’m not really sure.
When I first started playing BM I didn’t really like it until I was geared enough to survive the onslaught. You don’t get 3v3 until level 50 so the only form of pvp you have at the beginning is battlefield(20v20 or 10v10). You will feel really powerless but if you endure that part it will pay off. Since a geared BM can still go ham in group fights without getting bursted instantly.