I'm going to more or less echo Kordovero and Double AA, but put it succinctly.
Yes, there is a difference, and it will matter.
Here's why:
If a person converts by any standard that is not universally recognized, then that person will not be regarded as Jewish by those with stricter standards.
Orthodox conversion requires more than Conservative or Reform conversion. It's a simple matter of fact. Israel (so far) only recognizes Orthodox conversion, and only those performed by Orthodox rabbis on a pre-approved list. An unrecognized conversion will significantly impact one's ability to move there, and it may, in fact, make it impossible.
Hence, if a person converts under Reform or Conservative auspices, an Orthodox conversion would be required later if that person were to decide to join an Orthodox congregation or to move to Israel.
Furthermore, for a woman in particular, if her conversion is not recognized, her children will not be regarded as Jewish, either. If there is any desire to enroll the children in a Jewish day school or any inkling that the convert may want her children (or recognition that her children may one day decide) to join an Orthodox community, having a mother who underwent a Conservative or Reform conversion will pose a problem for them.