The honest answer is I can't answer that for you. You've got to go try both phones for yourself and decide which you like better. They're so similar in terms of features but different enough in terms of how they look, feel, and work that you really have to play with 'em both in order to decide. But, hey, I'm the expert (I guess), so here's what I think:
I'd take the Glyde for two main reasons. First, I like the form factor a little better. Glyde is actually thicker than enV2, but it's narrower and lighter and so I just like the shape of it more. I also like that I can operate Glyde one handed with the phone closed and still get to most of its features - you have to open enV2 up to access its advanced functionality.
Second, Glyde's camera is a litlte bit better than enV2. They're both middle of the road 2 megapixel cameraphones, but Glyde adds autofocus and, more importantly, a flash. It's not a real flash, but it's a flash assist light that makes it possible to get close-up shots of your friends in dark places (like restaurants or clubs, or outside at night). Don't buy Glyde only for its camera, by any means, but in terms of comparisons it's got a slight edge over enV2.
Also, Glyde has an HTML Web browser while enV2 is "mobile Web" only. That said, Glyde's screen is small enough that it's hard to do any heavy surfing on it. And the touchscreen is quirky and can be frustrating when you're trying to click small HTML links on a Web page. But you can get to more of the Web on Glyde than you can on enV2.
On the other hand, enV2's keyboard is larger than Glyde's and it has a dedicated D-Pad. I liked both QWERTY boards pretty equally, but some may find enV2's a bit more comfortable. And enV2's external dialing pad is easier to use than Glyde's touchscreen - especially for texting.
Really, though, they're on pretty equal ground and picking one is a matter of personal preference more than anything else. Glyde has a few more features, enV2 is a little larger and a little less expensive. I'll have a comparison video up within the next hour so you can see for yourself.
But really, you'll have to try 'em both out and make a choice. And, of course, you can also go with Voyager or Alias if you're shopping for a VCAST QWERTY phone. Decisions, decisions ...