My plumber strongly advised against it. We had one in an apartment, and wanted in the house, but he talked us out of it.
With a combi-boiler, you've no hot water cylinder. So if someone is having a shower, and another person turns on the tap in kitchen for example, they're competing for hot water. Maybe it was a case of size of the boiler.
The other thing is the boiler is constantly turning on and off each time you use hot water, which seemingly shortens the expected lifetime of boiler. That's noisier than a pump would be. The pump can also be housed anywhere, it doesn't need to be near boiler.
Your plumber obviously knows more than I do. Just make sure you ask him the right questions.