Bitrix24 is definitely better than Teamwork. Think Asana + Dropbox + Slack in one and free. It has more PM features than most paid options - tasks, subtasks, checklists, automation, Gantt chart, dependencies, etc.
We actually switched from Teamwork to BoostHQ and I couldn't be happier. BoostHQ is easiest to use project management software that combines docs, spreadsheets, checklists, polls and discussions all in one platform.