Hopefully this will help some folks.
I have to significantly tweak every style that I buy from YamahMusicSoft because they generally don't sound like the demo even on the keyboard that they suggest for that style.
But over the years I developed kind of a process that can always make them sound as good as the demo and usually much better.
I'm assuming that people know how to change instruments on a style, are basically familiar with the on-board Style Creator and are able to update the effects section. If you have a question there I'd be glad to help and I'm sure there are those on the forum who know much more than I do also.
Here is the process.
1) Almost always the drums don't use the best kit. So I take Rhy2 and change it (normally Real Drums sounds best). If this sounds good, then I'm done. But sometimes the style developers don't even use the best pattern for the drums so in the sections that are lame I'll use Style Creator to replace Rhy2 with another pattern from another style that may give it more life.
2)Almost always Rhy1 is lame. Just a tambourine or cymbal. Using Style Creator I usually replace these in all variations with Rhy1 from a Latin style which usually has bongos/congas etc. It adds more dynamics.
3)Many times I'll also change the bass to Vintage Round. This or Electric Bass usually sound best.
4)One of the major flaws is that the electric guitars are usually lame. Sometimes the pattern is ok but the effects don't sound like an electric guitar at all. I don't know why Yamaha sets the effects for the guitars like they do. I have some settings that I saved as a User Effect.
Using British Lead Hard as a starting point I have the following settings for DSP1:
Type Lead
Preamp 10
Tone Shift Tight
Bass 10
Middle 10
Treble 0
Presence 10
Master Volume 10
Output 7
Speaker Type Off
Speaker Air 0
Mic Position Edge
Connection System
Then for all the guitar parts I play with the Mixing Console/Effects control until it sounds like an electric guitar. Sometimes I'll have to change the Volume for that part as well since it can be too loud after the changes.
If the electric guitar patterns aren't good there are several in the Rock Styles and Dance Styles that do. For these I'll usually have to use the DSP effect listed above to make it sound like a good electric guitar as opposed to a non-distorted funk guitar.
5) Almost always the Pads are drab. Just a single chord that drones. There are more lively Pads in some of the Rock Ballads and in some of the Dance styles so I'll generally replace those in Style Creator.
6)Phr1 and Phr2 are also usually non-existent or unimaginative most of the time so I'll usually find a funk type guitar and a lively synth sound from the dance styles and replace those as well.
After doing all that I usually end up with something better than they sent me.
Hope this helps someone and let me know if there are any questions.
NASAMike