Is there a difference between Excel V, Laser Genesis and V Beam for someone with rosacea and very mild melasma?

Firstly, even moderate to severe cases of rosacea and rosacea redness are treatable with an appropriate topical (and occasionally also oral) medications. The marketing and advertising for all kinds of "bells and whisltes" laser treatments these days tends to make the general public think first of these relatively expensive treatments, rather than the tried and true topical (and oral) medications that have stood the test of time. Moreover, unfortunately, the hard science to support the benefits of the light and laser treatments lags well behind the marketing hype to promote them. And all too many venues spout the purported benefits of the device they have around or have just purchased. You would be wise to consult with a board certified cosmetic dermatologist before jumping from one device to another. Remember the old rule: Keep It Simple.