Macerator toilets are useful if you need an extra toilet in the home and your foul drains are not in the right location. They can create noise and are prone to blockages if inappropriate things like wipes are flushed, but it’s often less expensive to install one than to extend your existing sewage system.
The building regulations allow macerator toilets such as Saniflo only when you already have a normal gravity type toilet (i.e. a macerator can’t be the only toilet in your home in case of power failure). The macerated (cut up) waste still needs to drain away to the sewer, it just uses a smaller diameter pipe and a pump. You need to apply for building regulations approval.
Pumped shower waste systems are useful if you need to pump water up to your drainage system.
Approved Document G (England) of the building regulations covers sanitation, hot water safety and water efficiency.
(Image courtesy of saniflo.co.uk)