I apologize in advance for my long answer. I can sometimes be too “wordy” LOL.
There are so many variables involved in making an atomizer recommendation, namely are you a Mouth-to-Lung (MTL) vaper, or Direct-to-lung (DTL)? MTL tanks typically offer a tighter draw, DTL tanks are more ‘airy’.
If you’re a MTL vaper, which I think you probably are, flavor is your primary goal. Making your own coils is possibly out of the question since you’re still new. So a sub-ohm tank is your best bet. It uses pre-made coils in various ohm ratings to suit your needs.
Or perhaps building your own coils might be in your future? In that case a “hybrid” tank may fit your needs. It can use both pre-made factory coils, or comes with a RBA (rebuildable atomizer) unit where you can make your own coils. Kangertech’s Toptank Mini is a good example. You get the best of both worlds.
You probably bought the starter kit version of the Pico 75 that comes with the Melo III Mini atty that only holds 2 mls of e-juice. You’re probably refilling often which creates the illusion that you’re vaping too much, when you’re actually not.
As an interesting side note, if your Pico came with the Melo Mini, a rebuildable head is available:
Eleaf Melo 2 RBA (ECR Head)
As for the short battery life, some other details are needed. Do you vape in Wattage mode or TC? If in Wattage mode, what is the power setting? The higher the wattage, the shorter the battery life.
Which brings me to the next question, what brand and battery rating are you using. Only stick to the quality name brands such as Samsung, LG, or Sony. Avoid eFest as they rewrap other manufacturers’ batteries and the mAH (Mili Amp Hour) ratings don’t always jive.
Battery ratings vary too. I use LG and Samsung 3000 mAH batteries. They last longer (to me at least) than a 2500 mAH battery.
Don’t write off the Pico 75 so quickly. I’ve had mine for over a year, and it still vapes fine. I now vape exclusively in TC mode using DIY stainless steel 316L, 28 gauge wire. I reduced TC wattage input from the factory default 75 down to 55. I can vape all day on one battery. I adjust the wattage as needed, increasing power as the coil and wicks “age”, so to speak.
But if you want to upgrade to another device, the Revenger X sounds like a fine mod. I’ve liked the looks and features since it first hit the market and thinking of getting one in the future.