I've used both on my startup (as well as Crisp) and ALL are excellent at what they do. It comes down to your use case. We ended up with Intercom because their

I've used both on my startup (as well as Crisp) and ALL are excellent at what they do. It comes down to your use case. We ended up with Intercom because their user/company model fitted our SaaS (i.e. one user login could be associated with multiple subscriber companies) and we could easily filter by company or users to see total activity and provide support. Drift and Crisp were modelled on the 'one user, one company' concept. We got on the Intercom startup plan too, which really helped our cashflow (we are bootstrapped). However that runs out in a month or so, and the full price is going to be eye watering. Wish they had a stepped plan over 3 years like HubSpot which would help slower growing companies.