^ good call.
There seems to be a pretty variable response to the cyclobenzaprine as far as sedation goes. Some people are rather sensitive so 5mg may be preferable as a starting dose for potentiation purposes. If you are more familiar with what 10mg does for you and/or you tend to need larger doses to produce substantial sedation with drugs across the board, feel free to start at 10mg. If you enjoyed 25mg of hydrocodone and don't have experience with cyclobenzaprine, you may want to start with 15-20mg hydrocodone and 5mg of cyclobenzaprine.
15mg Hydrocodone and 10mg cyclobenzaprine won't be dangerous, it may just not be a quite as enjoy as a larger hydrocodone:cyclobenzaprine ratio. Most people do not find cyclobenzaprine recreational so prefer to use it to boost the opioids just a little bit, not by a factor of 1.67 so don't expect 10mg of cyclobenzaprine to make 15mg of hydrocodone feel exactly like (or as good) as 25mg of hydrocodone. You may have as much or more sedation doing that, but less euphoria.