I do not think anyone could give you an %100 accurate answer because we do not know what your vaping habits/preferences are like now.
I would suggest you do something like I just did myself, go and watch reviews on youtube that show the products in question and hopefully have pro's and cons for both.
Differences of the 2 mods you mentioned for consideration:
X Cube Mini
Smallish sized box mod
75 watts
CON Very Wiggly Fire button bar
Flashy led and blue tooth control
CON buttons on top of mod, juice can get inside
PRO TC in Ni Ti and SS
$45 estimated
CON short delay in firing and producing vapor
CON battery cover wiggly/loose
USB port on Bottom for charging, I am not a fan of bottom charging ports.
Comes in Red, Black, Stainless, White.
Koopor Mini
Smaller sized box mod, more rounded edges.
60 watts
Standard fire button, slightly wobbly
nothing flashy
PRO buttons on side, less chance of juice getting in
TC in Ni and Ti (CON No SS)
$40 estimated
PRO Better battery cover
USB port on bottom for updates only, separate charger required. Would suggest a spare battery.
Comes in Silver or Black
The one I bought after a couple of months of scouring reviews:
Wismec Presa 75w TC
So small you can hide it in you hand (minus tank), VERY comfortable, surprisingly heavy and solid. Dead Sexy (IMHO)
Fire button leans into the mod like this \ so squeeze and vape, left or right handed front back it does not matter
Aside from front fire panel button, 2 other buttons at lower front of mod
TC-Ni/TC-Ti/TC-SS/VW/Bypass Mode
USB port just below the 2 front panel buttons for BOTH charging and updates. This allows you to charge it while it stands upright with a tank attached.
Rear battery cover is taco shaped verses flat panels in mods above. Has just a slight up/down wiggle with accompanying dink / donk sound when physically moved. Cover will not move when shaken. I could not get it to fly off even picking up the mod by the cover and trying to shake the mod off the cover even with a tank attached, very strong magnets.
$39.99 base, $44.99 with shipping from angelcigs as they were about the only ones I found with it in stock when I ordered it. (china company, shipped from a ware house in California, and I had to use paypal as a lot of american CC's auto deny anything china based even though they have a USA location that most items ship from. ) Arrived in 4 days.
Comes in Silver or Black.
Comes with a 510 to EGO adapter, USB charging/update cable.
As to what tank to pair with any device, the answer depends on how you like to vape. Do you sub ohm already? Do you want to just blow big clouds and do not mind a warm to hot vape? if so the the tfv4 will probably be great. Do you want a cool vape and are more concerned with flavor? If so even an aspire K1 will work fine at 10 watts / 4.2 volts and produce decent vapor, I am running that while I figure out the crown tank. I can vape for days before needing to recharge it.
Mine shipped with 1.01 Firmware, I just spent 10 seconds grabbing the 1.02 firmware and like 2 seconds installing it.
This added the TC mode for SS. FYI Wismec is associated with Joytech and I feel the quality and support of that really shines here.
If you get a black mod and want a sub ohm tank to match, the Uwell crown tank is also dead sexy in black, I got it along with an extra glass in translucent black. I also bought the RBA for the crown.
PS: I am not trying to get you to buy a Presa, I simply liked it more for me than anything else available, even $200 mods. I guess you can probably tell I really love this mod
In any case good luck and happy vaping!