I see no reason at all why anybody in their right minds would put in an ecoTEC Pro, the cost difference between that and the Plus, which is a better boiler, doesn't justify having one. The Pro is a bit cheaper to buy but works out more expensive to install as it takes a bit longer and you've got to buy more bits for it, so overall if you're going to have a Vaillant get an ecoTEC Plus. Also, the warranty on the Pro is much shorter than it is on the Plus, assuming you're using a Vaillant approved installer.
Personally, if it was my own house and I was going to put in a combi, I'd put in an Intergas Combi Compact HRE which is a better boiler for about the same money.
Having said that, I'd be dubious about putting any kind of combi into a 4-bed house, your hot water requirements will almost certainly outstrip the available performance of even the most powerful combi, and the Pro24 is nowhere near the most powerful combi available. How many people are living there currently, how many do you expect to be living there in the future, and how many bathrooms / shower rooms do you have?
What does he mean by eco radiators??
