It's important to keep in mind that when you find the kind of information that you have re: lexapro, you are often reading the exception rather than the rule. People are more often to speak of negative experiences rather than positive. This is especially true in forums seeking others who have had negative experiences with medications. I have found A LOT of websites with all kinds of bad experiences with the heart medications that I'm on, but, other than the allergic reaction to one, I haven't experienced them. If people are seeking others out on the internet, they are generally looking to share experiences. And when people have negative experiences and are researching on the internet as to the cause, they are more likely to respond to such sites. When people have positive experiences, they're not out there searching for more information and, therefore, they are not finding those sites.
While it's good that we are aware that negative side effects do happen, it's important to remember that they don't happen to everyone and that your experience may be completely different. It's also important to remember that your doctor prescribed this medication because the potential benefits outweigh the risks.
IOW, take it with a grain of salt; what you're reading on that site doesn't represent a controlled group of patients taking lexapro. It's heavily biased.
But, to answer your question, I have gained weight while on lexapro, but I started the weight gain prior to starting lexapro and also take synthetic progestin which could cause the weight gain, too, so I can't pinpoint it to the lexapro. But, even if it is the lexapro causing the weight gain, I personally wouldn't discontinue lexapro. It's made that much of a difference for me.