They basically have the same chip, the S version has screen upgraded over the rx200. Since you ask, i will suggest the 2/3 version since its newer and you have the ability wether want to use 2 or 3 batteries.

Ori RX200 = Cheap, small screen but huge.
RX200s = Slightly more expensive, big screen, still huge.
TwoThirds = Most expensive, big screen, can be medium or huge depending on configuration.

That said, the price difference between the three is actually quite small lol. IMHO, save up and get the TwoThirds. Why? You can go medium or large according to your needs... it's like having two mods at once.

Here's my review on the TwoThirds (my current backup multi-batt mod), hopefully it helps: http://goo.gl/reldJz

That said, even if all the RXs go to 250w with three batteries, I still think my VT133 fires and TCs better. And while VE is still having their VT sale, it's only a little bit more expensive than any of the RXs. Maybe worth considering IMHO, if you don't mind having to learn how to eScribe.

If you don't want to bother with eScribe, then get the RX2/3. It's still a very solid mod.

Nope. At 50w it will mostly buck from both 2-cell or 3-cell configuration. For all intents and purposes, it should pretty much feel exactly the same, though of course the 3-cell setup will have longer battery life.

Above 150-200w there might be a noticeable difference, as a 2-cell setup will probably have to boost more then the 3-cell one - there will be a noticeable difference in firing characteristics due to this (especially as your batteries drain more and more in use).

Price should be around RM200-ish for the RX-TwoThirds.

Sib Will do. Seems disassembly for the Nugget is plenty simple too.

The only mod I have no balls to take apart for now is the TwoThirds - seem like it's gonna have lots of small parts that will spring loose the moment I open it up. Maybe later.

A few questions u may wanna ask yourself first:

1) Do I need/will I benefit from the transformation capability between 2 and 3 batteries?

2) Will lifting, holding and putting back down the mod numerous times each day be ok or become a tiresome task? A 3 battery mod can be rather heavy.

3) Does the ergonomics of the mod in 2 and 3 battery mode suit my hand? Will it be comfy to grasp or awkward to hold properly?

If all of the above are ok with u, then go for it! You'll get longer vaping time with 3 batteries @ 50W compared to 2 batteries.

Do you mean more kick as in more wattage power?
Then RX should serve you well with longer battery life.
Ayam not sure how much should the TwoThird be, but the RX200 is at RM220 in VapeEmpire.
By getting an RX I should remind you that it does not have balance charging yet so I really recommend you to charge via external charger and get 6 batteries so you can swap those on the go.

If you have more to spend, VT133 is on sale as well.

Then get the VT133. DNA inside. Guaranteed more kick. Just need to learn to adjust using PC and eScribe, that's all. Below RM300 (just) from all Vape Empire outlets as long as the offer still stands. That's cheaper than anywhere else in the world, Internetz included.

Not that the RX23 doesn't kick... it just doesn't kick as hard IMHO (especially in TC). It's a backup for my VT133 for a reason lol, even when the VT is rated to "just" 133W.

Of course, if you can't justify paying the extra dough for DNA, the RX23 works just fine really. In 2-cell mode it does hit considerably harder than the Pico at 50W TC (though it loses to my VT133).

Also to consider, the Smok H-Priv, if you don't mind ordering online (cause seems nobody's stocking Smok stuff locally any more). Around the same price as the RX23, hits better (according to TristanX).

Personally now waiting for the DNA167 mods to hit (DNA250 using 2x18650). First out is the Boxer (as always), hopefully HCigar (or even better, LostVapes) follows suit.

Maybe you should consider higher nic level in your ejuice if you're looking for the satisfying throat hit? or maybe change your tank altogether?

50w on pico and 50w rulo might not have any noticeable difference you know other than longer battery life of course.  

True, though if he's not used to it he'll get nic sick from 12mg rather quickly without changing his vaping habits. And trust me, you can get nic sick *very* quickly.

If he just wants a harder hit, maybe more wattage (50->80)? Though that might burn (and burn *through*) his juice faster also, depending on his tank/coils/wick.

What battery you're using on your pico if I may ask?

my giveaway prizes from Suicide Bunny has arrived     

what i got is a 30mm Triforce Tank, 120ml 3mg Mother's Milk, a camo cap, and a t-shirt 

Remember to have 5 batteries if u interchange 2 and 3 batteries mode. You gotta keep the marriage. Ageing will be different once you remove 1 and use only 2.

Also, I've been pushing my mods lately. LG HG2 heats up fast even when not maxed out. Sony VTC4 stays cool at 140-200W.

IINM you can just marry three (for the initial first time) and then cycle through the setown EVERY TIME yout charge. 1-2, 2-3, 3-1 - but you REALLY need to keep track of your cell usage this way though.

Or at least that's what Mooch said in his last RX23 specific post up on Reddit.

Soscili: https://goo.gl/aOajJf

Also, you probably need an external charger. The TwoThirds (like all the other RXs EXCEPT the original Rulo DNA) DOES NOT have balanced charging

Don't know how far you wanna go. If you want to go crazy, definitely Griffin 25.

Also, Altsmo selling TFV8 at RM130. The RBA on this one can fit 7 wraps 3mm clapton dual coil or 8 wraps Kanthal/SS/Ni200/Ti 3.5mm dual coil. Maybe more too.

Big tanks may need bigger coils to cope with the increased air flow. Yeah, TFV8 doesn't have small coil builds in mind when it comes to RBA. Too airy.

The Eagle is *actually* a Subohm Tank... in a sense. It uses precoiled decks, but the cotton is replaceable like normal RTAs. I'm not sure if you can actually recoil the pre-made decks themselves, but that's not what it was made for. Not sure if it comes with an actual RBA section either.

The Griff is a normal RTA, where you have to recoil and rewick yourself.

Which one better? Depends in how cash-flush you are (precoiled-decks cost considerably more, like OCCs/attys for other Tanks... but being able to rewick yourself means that it'll last longer on the Eagle) and how much you like to fuss with building your own coils (Tanks are of course easier to deal with compared to RTAs).

The size. How much you can build depends on your deck? The stock coils for my TFV8 RBA is 3mm 7 wraps fused clapton.