I'm sure that the flash itself would only be slightly better than the pop up flash that you currently have. I guess it all boils down to what you are trying to accomplish with the flash. If you are just looking to be able to bounce light, then it should work for you. However do keep in mind that there are limitations with a small short flash such as this... If you are using a long lens with hood, the lighting may get blocked by the hood in a straight forward situation. If you are bouncing the light, then this would not have so much of an effect on the photo. Maybe purchase the light try it out see if you like it, then base your decision on that.
Otherwise you may want to search elsewhere for a small light that does not have such a low profile, but will fit within your budget.
Maybe this may work for you
Targus Flash this would raise the flash above the profile of the sunpak and would probably not be as affected by longer lens configuration. If you can spend a bit more I would also suggest looking into a manual flash like a Yongnuo.
HTH.