Have you actually looked through a Vortex? The Nikon was a good scope for its size, and I used mine for many years as a second scope. IMO and that of every review I have read the Vortex is better.
I have given my opinion as the OP asked for. For £399 -although it may have gone up by now - the Vortex is a bargain and for that price you get a superb warranty which means the scope should last a lifetime- as long as you don't buy a grey import from Japan.
I've tried the Vortex but I've not given it a thorough, super-critical test. I've no doubt that it is an awesome scope, and I've no problem with you sharing your honest appraisal. But I also have an interest in encouraging information content in discussions on BirdForum, so I prefer that reviewers explain what they mean and the bases for their claims. Without such details, I see little value in reviews for the OP and other readers of a thread. I've not seen a prismatic scope that performs any better, with respect to resolution and color, than the 50ED and I'm not sure it is even possible. Certainly, I've seen models (e.g. Opticron MM4) that did as well as the ED50 and I'm sure, based on your and other reviews, that the Razor does likewise. I've seen a number of reviews (e.g. that of the Porters) that rate the Razor over the 50ED, but not for resolution/contrast/color, but instead for things like eye-relief, FOV etc that are entirely eyepiece dependent and thus not relevant to a discerning user (i.e. the sort of person who would be fretting the details by asking questions on BirdForum). Reviews of the 50ED with the 13-30x zoom are best interpreted with knowledge that that eyepiece is OK but not Nikon's best (Even amongst zooms, the 13-40x is sharper and offers higher magnification, though its FOV is still poor). My biases are such that I like scopes that offer eyepiece options, I like FOV, and I like to keep scoping about aiming and focusing without need for (especially with a travel scope, since they can't support high powers anyway) zooming. I like my travel scope to be as small and lightweight as possible with no-compromise-for-the-size optics. Those preferences lead me to the Nikon 50ED because it is optically as good as it gets and because it offers compatibility with all past Fielscope eyepieces and thus options that can be super sharp, super compact compared to the competition, wide field compared to the competition, long eye-relief, and appropriate magnification for all-around use (rather than zooming out for FOV and zooming in for attaining a standard scope magnification of ~30x). For me, that translates to the 50ED with the 27x WF eyepiece (a very small eyepiece that contributes substantially to keeping the overall package small). Given that a fixed-power eyepiece is unlikely to need service and that the 50ED is available body-only new for ~$325 from Japan, I'm willing to give up the warranty. I don't care if others have the same preferences or make the same choices. I do care and appreciate it when reviewers explain themselves when giving advice. I regret that I didn't do a good job of that myself, in my first post in this thread. I usually do better. I said that I would never choose the Razor over the Nikon but I didn't explain why (Answer: it is optically at least as good, offers interchangeable eyepieces, and thus can be smaller, lighter, have better FOV and eye-relief at working magnification, and can be cheaper).
--AP
