Dual Mesmer works well most of the time, but struggles throughout WoC where enchantment strip makes the emo less effective and hard hits can quickly overwhelm the team. This comp excels throughout the toughest 4-man content (WoC) and also does well throughout other 4-man areas.
Even though Dual Mesmer works for most 4-man areas, it has a lot of trouble in Shing Jea VQ's with heavy spike potential (Nagas, Crimson Skull, sometimes Kappas) and 4-man WoC content since the E/Mo can't keep up with healing. This build however shines in areas like those, giving more than enough sustain with the ST backline, and the healing from the SoS Resto. Single Mesmer is enough for damage when paired with a damage-based player build, especially melee (Splinter Weapon).
Great alternative for dual mesmer. This team trades damage for a little more defense, but still gets the job done easily. ST gives you a lot of safety in Shing Jea, while dual mesmer is a bit spiky there. Both have it's clear pros and cons, and both deserve to be listed.
Strong team which gives ample defensive capabilities, and supports melee damage significantly. Might not clear quite as fast as dual mesmer, but is much more reliable.