Hornby DCC controller.

[chrispearce]

Considering building a layout. Is the Hornby DCC controller any good for N Gauge? If not what would people recommend which doesnt cost the Earth?

[ntpntpntp]

Which one - Select or Elite?

Early Selects where found to be out of spec on the DCC signal, but that was fixed with firmware updates which also allowed it to read CVs   IIRC, so if it's a Select get it updated by Hornby if necessary.
Elite is I believe a better unit.

Plenty of other discussions on here and on Facebook groups about "best DCC system" with plenty of different opinions
Any particular reason you're looking at Hornby DCC?  Other systems out there which you might find to be better suited.  You need to visit a DCC specialist shop or exhibition trade stand and have a go of different systems' user interfaces, discuss your requirements and see which system seems best for you?

As for suitability for N gauge: N, TT, and OO all run off the same nominal 12V DC or  14-15V DCC so gauge is pretty much irrelevant.