I haven't used the E30R, but I've owned the LD30 for a month or so, and can give you some quick feedback on that one.
I did notice the slight greenish tint, as mentioned above. It's not bad enough to worry about, but it's there, compared to my several other Fenix lights.
Definitely doesn't tail stand, but I'd much rather have the tail switch, than not.
The dual use clip is great. You can clip it on a hat, and since it won't tail stand, you can clip it to a box or something if you wanna use it with a diffuser pointing up. My Fenix E16, another new model, has the same style clip, and it's great.
The beam is a little floodier than other Fenix lights I have that take the same battery, but there definitely is a good hot spot, and it gets real bright.
I do like the size of the LD30, as it's not much bigger than the battery it takes. I've been carrying it every day in a front pocket, clipped, and it's practically un-noticeable. The similar older PD35Tac, one of Fenixes best selling lights, is around a full inch longer than the LD30, and over an ounce heavier, approx 3 oz. compared to 2, so I tend not to edc the 35Tac due to size, although the beam is one of my favs. The new technology Fenix has been using on the heads / lenses is really reducing the size.
Being small, the light does make some heat on turbo at 1600L, so the step down feature is good. I don't usually use my lights on turbo for extended periods. On the LD30, high at 800L is almost as bright as turbo at 1600. It's good to have, but to me it's just using up the battery and making too much heat to use turbo for long periods with small lights.
Hopefully some of that will help you with your decision. The LD30 is definitely a thumbs up on my end. I don't care much about lights being rechargeable through a usb port, as I have chargers for the 18650. Also, Fenix has some cold resistant 18650 cells, if that applies to you. I got two to try this winter for vehicle lights.
Good luck.