No. The "e" series is the current series. The "i" series is the prior series. Most reviewers like the "e" better. Many people find the grado's too hot in the treble, so the "e" series attempted to tame the treble a little.
Actually, I think it's the RS1i that is preferred over the RS1e
At any rate, the only way to tell if you like them is to listen. Both series have the signature Grado sound, so listening to almost any grado will give you an idea of the signature.
In general, the -e series is preferred to the -i series of Grados, but there are exceptions. Folks prefer the RS1i (which at one time was the top of the Grado line) to at least all but the most recent versions of the RS1e (weasel wording because the most recent RS1e has the driver flush, not protruding, from the ear cup and is found to sound better than most of the RS1e line, where it protrudes and even touches some ears).
There is an on-going test right now on the current top of the line, PS1000 vs. PS1000e, where several Grado experts have both and are comparing them. Seems to be about 50-50 preference on that (see PS1000 thread).