Tilemap OR Objects to manage ground layer ?

[flashpapa]

Hello everybody,
I'm doing a little game plateform for fun and for the ground management and for more speed, I wondered if was worth better not use (for optimization) :

- Tilemap : But I feel that after a certain number of box it starts to slow down... (and i can use player.body.blocked.down to know il player is landing)

 

OR

- Objects that define the ground and far fewer (but i loose player.body.blocked.down to know il player is landing)

 

And that's make ->

And all mixed ->

 

I manage this with tiled like that ->

 

What is the best practice to design ground  and manage ground collision to keep a max of fps ?

thank for help and this great forum 

Here the sources.zip