Mara will win the dps war - that is what they are designed for. They are more squishy, but they become survivable with the more skill you obtain. Juggs are great at being teammates, but (at times) can take awhile to kill people, bursts aside. If you are being a good teammate, you will not be a burst jugg. Some may disagree with me here, but the best dps are mara's, not juggs. Juggs are great at giving solid damage, good protection, and can be great at peeling away players. They are incredible at providing an offensive/defensive combination. As an Immortal Jugg, there are few people that can take me down from an offensive standpoint, including dps. If you are good at Jugg, you outlast DPS. That isn't as sexy, but you'll win., especially if you have your cooldowns. Just what I've noticed so far. DPS/Mara will win the damage count every time. But a solid Jugg can whittle away a lot of that DPS through mitigation. Question being, can that same jugg take down a healer being healed? You'll figure it out. I love both specs. I'm a Jugg though, so I'm biased. Just run with it and enjoy your benefits.
TL;DR - if you go with your role, you will win regardless.