You're going to get a variety of responses...but I'd be interested in knowing of those responses, who has actually owned both pistols. (I have.)
For me, Glocks are not comfortable in my hand. The SD9VE is very comfortable.
The stock Glock trigger is better than the stock SD9VE. Both can be "improved" with aftermarket products. Personally, I don't mind the heavy trigger on the SD9VE, because a light trigger on a gun with no safety makes me nervous.
Glock beats the SD9VE hands down when it comes to aftermarket parts, accessories, customization, etc.
There are a couple of places where the "value" aspect of the SD9VE shows...like the rear sight which is plastic (but then, so are both sights on the stock Glock) and the stamped metal slide release. As far as I know, there are no options to change out the SD9VE slide release. You can get a steel guide rod assembly and an extended take down lever for the SD9VE from Galloway Precision, and other than night sights and a Hogue or Pachmayr grip sleeve, that's about all you can do to a SD9VE (other than the striker and trigger kits, of course.)
Magazines can be hard to find for the SD9VE, and parts and magazines can be found for Glocks just about anywhere. I'm surprised they aren't carried in convenience stores.
Glock has a reputation for reliability and accuracy. The SD9VE is generally very reliable; some people have trouble shooting it accurately due to the trigger, but that can be overcome with practice.
Some people swear by, and some swear at, Glocks. They certainly are recognized. A SD9VE won't get you bragging rights mainly because people think it's the Sigma (whose bad reputation lingers on), its low price, and because a lot of people just don't know that sometimes a good gun can be had for a good price.
Glocks sell around here, new, for around $550 (more with night sights.) Academy Sports regularly has the SD9VE for $319. You can buy the SD9VE, and put that $231 saved toward ammo, magazines, and a holster...or night sights and a trigger kit. If you possibly can, find one to rent and shoot first, before you buy one, to make sure of the trigger, and how it shoots for you. However, if you want a Glock, then after a while the extra $231 you paid for it won't even be remembered.
Good luck in your decision.