Honestly, Night Game and day game have their easier parts yet harder parts.
During the day, conversations can slow down a bit. You don't have a huge amount of outside stimuli or things outside your control, like the music, the dim lights, the crowd, etc. To me, if I want a day of conversational game, day game is where it's at. The world can slow down a bit and I can really work on my verbal skills.
Night game makes verbal skills much harder to practice, yet at the same time you can work on elements of your non-verbal game, as well as your 'natural' game. At night, I like to go out with others. Best case scenario a crew of fully trained wingmen, led by one of my mentors. Worst case scenario one of my friends or roommates. Either one, you can convey yourself as someone fun to be around, even when you're not directly talking to your 'targets'.
Obviously, night game is where my dance game comes in. In fact, last night I had an awesome night of dance game practice, at a spot I was at for the first time.
Now, similarities between day and night game are there. You can still show leadership qualities in both situations. Example being yesterday, where I went out to the mall and actually led a store clerk during day game...then at night, led a crowd at a club when the DJ played the 'cupid shuffle'. You can foreshadow a second encounter in both situations, and at least get contact info.
Basically, I think its best to practice in both situations, that way you build overall awareness.