simple repeated measures syntax - lme vs. lmer

Question

I'm trying to look for significant effects on "similarity" (of "isinpair" and controlling for time effects) using repeated measures with an in group sample. The intervention "isinpair" occurs after a short period of time (time intervals aren't equivalent, but there are many occuring with in a relative short time).

The question seems a variation of R's lmer cheat-sheet

Unfortunately, I am quite hazy about the syntax (and underlying statistical differences) of lme vs. lmer. I've seen both recommended for similar tasks.

1. Are these two examples accomplishing what I intend? How equivalent / different are they? Which is better illustrating what I'm hoping to examine?

   lmer(similarity ~ 1 +time*isinpair +(time*isinpair|user1), data=nozeros) 
   
   lme(similarity ~ isinpair*time, random=list(user1=pdBlocked(list(~1, 
                      pdIdent(~isinpair-1), pdIdent(~time-1)))), data=nozeros)
   

2. How does this compare to:

   aov(simscore ~ isinpair * time + Error(user1), data = nozerosdemo))