Let Bus Direct from CDG

I haven't, but what I would ask is if the negative reviews related to things that would bother me or not.

I've taken Le Bus Direct, or its predecessor, a few times, and thought it was perfectly fine. We took it a few years ago when we arrived the day of a major transit strike, and despite the horrendous traffic it made good time.

We took it in the other direction from Eiffel to airport. Worked well - no transfers, no stairs, reasonable cost.

We've taken it several times.
It's comfortable, has only a couple of steps up into the bus and it negotiated traffic efficiently whenever we rode. I've seen complaints that one has to wait for the bus to come at the airport, but that's to be expected. It's not a private limo service. The other complaint I've read is that it lets you off at a predetermined stop, not at your doorstep. Again, it's a bus not a private limo.

*I like it very much. But it depends how many people in your party whether it's worth it, since taxi rates to/from the airport are fixed.

It's a more comfortable (and more expensive) alternative to the RER or RoissyBus, if you're staying somewhere that's convenient to a Bus Direct stop.

Note though that over the past few months, they have had mini-strikes from their drivers, making the service less convenient. That strike is still advertised now on their site. If you consider taking them, be sure to check their site closer to time when you travel.