I'll post only because i see the experts have already provided good advice for you. I have the same experience with the IKV 510s, specifically, they seem to allow the juice to feed more generously. And, because its the same brand and ratio of 60/40 (PG/VG) I've always used in the Reo I tend to believe its some kind of atty magic. When I vape with these I get more drops of juice in my mouth than usual so I just don't use them. I rely on the IKV 306 for really good vapes or an IKV 801 LR (with an AvidVaper Stealth Adapter) but atty choice is such a personal thing I'm not endorsing either. You will eventually find your go-to atty, I'm sure.
Lately I've used the red AW IMR 18650 3.7v 1600mAh batteries from SuperTManufacturing.com exclusively in my Reo Grand and enjoy every single vape. There really is a difference between these and the higher mAh 'regular' batteries. I'm actually sorry I waited so long but batteries confuse me and it didn't seem logical that a battery with the same stated voltage as the one I was using could be very different. Oh, but it is. There's more oomph and warm vapor and it lasts until the batteries die. So far I haven't had one die even though they're below 2000mAh.
Hope this is more helpful than confusing and good luck, nerd.