Going solo is pretty much as fast as doing it with a group, even faster if you draw the short end of the stick and get a group that are incapable of learning mechanics no matter how many times you scrape them off the ground, or are incapable of hitting buttons and do less damage than your bog standard Sylphie. Worse if you manage to get an ungodly combination of both.

Do yourself a favor and gear up a melee DPS if you have one, Variant Rampart trivializes raidwides and practically nullifies tankbusters, and Variant Cure will pretty much carry you through everything so long as you don't eat like 2 or 3 mechanics in a row. Trust me, you don't want to solo a dungeon with a healer damage rotation, you'll be bored to tears like I was.