Is Object significantly less efficient then ref object over here

[solomonthewise]

this is my current code it runs but im wondering if it would scale badly or 
have weird behaviors.
    
    
     MalType* = object
        case mk*: Mk
        of mklist: lis*: seq[MalType]
        of mkint: intval: int   etc 
    
    Run

compared to this
    
    
     MalType* = ref object
        case mk*: Mk
        of mklist: lis*: seq[MalType]
        of mkint: intval: int 
    
    Run

or this
    
    
     MalType* = object
        case mk*: Mk
        of mklist: lis*: seq[ref MalType]
        of mkint: intval: int     
    
    Run