New brake pads may not bed in for a few 100 miles so brakes may be a bit softer for a while, but be careful to match pads to disc, there are combinations of disc and pad material that don't work well together - and as for people who fit high performance pads that have to get up to a high temperature before they have any bite (so are no good around town) - the least said the better.
there are abrasive pads (bite into the disc as the name suggests) and adhesive pads (which leave a thin layer of pad on the disc). Better to stick with OEM pads and discs as the car companies spend lots of time finding suitable combination of material for all situations, good bite with cold pads, not too much fade with hot brakes etc. and good wear life.
I once fitted 'Blueprint' discs and pads to a previous Jazz GD (good quality and not cheap) but took them off and replaced with Honda after I had problems with brake judder.