As long as you're an employee (as distinct from a contractor) then your statutory rights (i.e. those embodied in law) are exactly the same whether you're classified as 'waged' or 'salaried'. (e.g. you're entitled to Statutory Sick Pay from the 4th day of sickness onwards).
The distinctions between 'waged' and 'salaried' status are very blurred these days. (e.g. my contract says I'm on a salary but my pay statement is calculated on an hourly rate!). Every employer will attribute different meanings to these terms - legal definitions don't exist - so you'll have to find out exactly what your employer is proposing. (Look particularly at what they're proposing regarding overtime working. You might find, for example, that waged employees get time-and-a-half but salaried employees are expected to do a certain number of hours without any extra pay and then only get 'basic rate' after that. That's what used to apply in my job. Now we get 'basic rate' for all overtime worked).
Chris