It depends on your playing style to be honest. Either GS or BD can be played aggressively or defensively so it's up to what you're most comfortable with. Needles to say the BD has very powerful perks, grenades and super if you learn to master them.

There's a reason why some of the best PvP play as a BD and the perks are beasts. There's very little discussion about the optimum built and optimum gear and for a detailed guide visit us on r/crusibleplaybook

I switch between the two and BD does take some getting used to. Try it out for a while and see what you think, but give it enough time to shine. The reason why you might get killed using your super could be because you're too far away when activating or you're too obvious when approaching. Try activating behind a corner as oppose to the middle of a corridor or in plain sights of the fireteam waiting for heavy. Even better, try activating after a vertical blink and then blink again towards the enemy (there's a 1 sec cool-down on blink and the animation takes about as long meaning you can blink twice). It's very easy to aim a Feltwinter's at an approaching hunter and press the trigger so try and avoid the obvious direct approach e.g. by jumping behind the enemy, dropping down from an above blink or whatever.

I use to wreak havoc as a Gunslinger and just recently started playing more BD than GS. Obviously I found it more difficult and as if I was forces to bum rush. However, that's not the case and blink is great of escaping, quick draw is great for switching fast to you sniper etc. I play best within the mid/close range and I find both GS and BD equally rewarding. Find out what suits you the best and then go all into intelligent and discipline, don't worry about strength for Trials, especially if you plan to stay in the back picking people off or if you run with the two throwing knifes.

Hope that helped.