A while back, I started making a platform game in Game Maker, and made the ground/platforms in a tile based manner, with each 48x48 pixel area of the world as a separate object. This ran quite smoothly, but it made the levels a little bit repetitive looking.
Now I'm porting the game to Game Editor, and from reading the documentation, it sounds like it might work to make the entire level as a single actor, with one enormous graphic for the ground. This would be much easier than tiles (allowing to use my graphics creation program for level design, rather than having to do it in GE, whose interface I'm not very comfortable with, yet), and would allow me to make the level much better looking, too, but I'm afraid that it might cause either gameplay lag, or slow loading times.
So, do any of you have any experience with this? Which runs/loads faster, for a level of a platform game: a single actor with a single huge graphic, or hundreds of clones of an actor, with smaller graphics? And which do you recommend?