Hi everyone I think I'm not the first to wonder - since the history of the Leo name seems to be long and complicated. Anyway, I've switched over to using just the batteries for the Innokin Leo Pro. This is because my usual supplier, Vapour Room (UK - not to be confused with the US Vapor Room, who I can't comment on as I've never used them), have stopped stocking the Lea 800 batteries which I used to use. BTW, I can highly recommend Vapour Room as a supplier (disclosure: only that I've been a happy customer since I started vaping in Feb 2012). They said that Innokin have stopped production of the Lea 800 - and I can't find the batteries on sale anywhere else. So to the Leo Pro batteries. I'm using them with my original, first-ever choice of atomiser unit, the Lea 800 atomiser, which I believe is 2.0-2.2Ohm. Vapour Room sell the Leo Pro with the Innokin Tidy 10 clearomiser (2.7Ohm) as standard, but also offer an iClear 10 2.1-2.5 Ohm clearomiser on their Leo Pro parts pages. I haven't tried either of these clearomiser options, and would be interested in hearing what other vapers think of them. Appearance and battery life I went for the red colour, since I liked the look of the old Lea 800 Barbera Red batteries. The battery is the same length as the Lea 800 (90mm), but about 2mm fatter. The finish looks and feels more plasticky than the Lea, which had a slightly pearl-like finish. The pen cap screws on to the battery, rather than clicking on to the atomiser as in the Lea. This means that you can use any atomiser/clearomiser/cartomiser that'll fit inside the pen lid, and the pen cap will still secure onto the battery. Because of the larger size, I've now changed from using a PV (the Lea) that could just about be a very fat pen, to a PV that looks like a pen put through some kind of Fisher-Price/Early Learning Centre toddlerisation process. (If I spent much time in the leather-upholstered boardroom CEO world, I might think these kinds of proportions were normal for a status-symbol pen (e.g. Mont Blanc); but I'm not in that income bracket). I prefer the screw-on pen cap to the click on Lea one. One problem I found with the Lea atomiser/battery combination was occasional bad threading. Some atomisers just wouldn't screw onto some batteries properly. I think the threads got worn out in time, and the threads on the atomisers were not always perfectly made. Having the cap mechanically connected to the atomiser can't have helped avoid wear and tear: so with the Leo cap I know this is less likely to happen. The fit of the atomiser to the battery feels mechanically much more solid than on the Lea. The standard Innokin multi-colour red/yellow/green button, used to indicate battery charge, is different from the one on the Lea 800. That one was a round metal button, with the LED shining through a circular surround. The Leo button is matt transparent plastic, with the LED shining through the whole button. The button is scored in some way to diffuse the light: I like this look. This battery is rated at 1000mAh, 3.7V as opposed to the the Lea which was the same voltage but 650mAh. Given this difference in rating, and the fact that the Leo batteries are new, I expected to get much longer use from them than from my (old, well-used) Lea batteries. But I haven't seen much of a difference. 24 hours use seems to be typical before the yellow light goes on: and as another reviewer has commented, an Innokin yellow light means that you're going to get tolerable vaping from now on - but not for very long. However, though I'm not getting much more life from these in terms of time between recharge, the quality of the vape is unrecognisably different. I think I'm just using more power per puff. Vaping experience I've been using some favourite liquids: Hangsen Apple and Blueberry (6mg), Alba Vapours Maple Rum Tobacco (12mg), and FeelLife Amaretto (6mg). The experience is unrecognisable compared to the Lea battery. One Youtube reviewer (which I can't find now for some reason) found the vapour was cold and lacking in flavour. I don't know exactly what head unit (carto/atty) he was using: all I can say is that (from the perspective of someone evaluating only their second PV) is I find the opposite. One thing that strikes me is that the cartomisers Vapour Room supply are listed as higher resistance than the Lea 800 atomiser (2.0-2.2Ohm). So I'm using a lower-resistance atty than the "standard" Leo kit. The vapour production is huge. I was drinking with a friend this last weekend, who was pulling on a Vivi Nova screwed into a VV battery cranked up to max. I could almost outdo him in "clouds produced". The vapour is not particularly warm or hot - I've never experienced a particularly hot vapour from the kit I've used, and I'm fine with that. The flavour is intense. I can't explain why, when the Leo and Lea batteries are identically rated in terms of voltage. Perhaps some circuitry that maintains a higher voltage even under load has been improved between the two; or perhaps a higher-rated battery keeps its voltage up under load better? There's so much flavour that I'm having to rethink how I vape some of the stronger-flavoured juices (particularly the Amaretto and Maple Rum Tobacco): they're turning into special-occasion treats, like an after-dinner single malt whisky. If I vape on them constantly like I used to on the Lea, there's just too much intense flavour: I get slightly nauseous. Some notes in the Amaretto are so over-emphasised that I might have to get hold of a higher-resistance unit to go on enjoying it. I'd like to hear what people think of this device when used with the "standard" atomiser/clearomiser. Happy vaping!