Is the effect noticable? Is there anywhere on the wiki where I can see how much of a difference unique variants give?
Like, 10% atk spd bonus on low, 30% on med, etc.
Also, what would be the prefered calibur?
One with medium atk spd bonus or medium charge time?
... and these stats are approximate . . .
. . . each level of UV gives approximately a 5% boos in performance. for speed, it's about 0.025 second per UV level.
Each * level give a 10% increase in performance, as in, it does 10% more damage.
"Is there anywhere on the wiki where I can see how much of a difference unique variants give?"
Yes; see the article "Abilities".
ASI low is not noticeable. CTR low is, because it stacks up with a weapon's natural CTR medium to become CTR high.
About the Calibur: the charge attack is the entire point of this sword, so you should definitely look out for a CTR UV.
ASI: 4% each level
CTR: 7.5% each level
DMG: 7% each level
~meis
I really don't notice a difference until I hit med/high.
I can tell the difference between ASI low and no ASI. Some people say it isn't noticeable, but it is to those that are observant. Now, does ASI low really matter? Not really, but it is better than none and it comes on my Crown of the Fallen for free.
Personally I ran an Ascended Calibur with UV CTR Low along with full heat CTR Med and an Elite Sword Focus Module CTR Med for a total of CTR Ultra for a long time. It is easy it get nice ASI &/or Sword DMG+ from gear & trinkets. I would not take a Calibur through the last craft to Levi though unless it had at least CTR Med though (so it would hit Max with heat & a trinket).
Thing is though, once you switch to specialized damage swords you will not use your Calibur very much at all. I pretty much only use mine for Vana's mask these days. I used to keep my Levi around for quick turret busting in arenas, but the Warmaster Rocket Hammer has replaced it for this role.
As far as ASI goes, I really hate to run with anything less them ASI Med. Just messing around in the ATH it is hard to tell the difference between many of the ASI levels, however, once you get used to say full Vog's Very High ASI anything less becomes painfully obvious. I've had problems with taking hits when not running ASI, because my shield did not come up as fast as I was used to. ASI doesn't technically make the shield come up faster, but it makes the swing happen faster and the put up the sword animation runs faster, which results in less time from swing start to shield up when using ASI. If you want to experiment with ASI get a Swiftstrike Buckler & go rip through T1/2 (this will give ASI High to both swords and handguns).
The effect is slightly noticeable, though it might be hard to notice unless you go back to not having the UV after using it for a while. There is no solid number on the actual percentage increase because that information has never been publicly released.
ASI and CTR operate differently, as do most weapons. With bombs, CTR is really the only one worth getting for non-bombers as ASI would be wasted. For swords and guns it depends on where the weapon shines. An example would be the Antigua lines. Their charge is underwhelming, so an ASI boost would be a better benefit, same for the Callahan, but if you look at the Alchemers, they have a much better charge and, being two-shot weapons, would take more away from a CTR boost.
Also, this should be in The Arsenal. You should move it.