1) Are you shooting barebow or oly recurve?
2) would you consider your hands small, normal or big?
3) Would you consider your hands skinny , normal or “meaty” ?

Do you have any form photos ? (where you shoot?) These are mainly to see which way you hold the grip (the Korean style or the 45 degrees knuckles).

In general, the master is a good all-rounder, low torque grip. The master will also fill that pleasurable point in the center of your palm too . You’ll know when you have your hand correctly on it
The tax evasion is a little more pronounced in the bottom of the palm and would be best suited to a Korean style shooter. It also puts pressure on your wrist kinda likea ball grip would. You can imagine the Tax Evasion as those bulky handles that come on the wooden takedowns but with a heavily modified lifeline. Best for “meaty” hands

The Caerus gives more definition to the middle of the palm, with a thin throat. Best for recurve. Defined lifeline (unlike the W&W grips :/ )
The Kteenos is for large hands as the lifeline goes straight down to accommodate that big hand. Still, a slim throat.

The Master would support/fill more on the upper side of the palm, while the kteenos would support the lower parts more.
The Caerus is in the in-between of these two.

The thumb positioner is by default added in the Master and Kteenos, but can be added to the others as well! The positioner is a welcomed addition to almost all gripsbut there are some people that do not like it! It gives a sense of direction and a reference to the center of the grip. One certain reason to NOT include it, is a non standard thumb physique. In all other cases it is a bonus. 
On those options, there is the lifeline option as well. While at the Master it is a no brainer, it is not really needed on the tax evasion. The lifeline ridge is only 0.7mmin height so it does not go further in your hand than your skin tissue. It is not really felt when shooting, just when “locking” your palm on it. (meaning that you usethe lifeline ridge while sliding the grip on your palm, to find the position. Once you start putting pressure on it, it disappears)

Regarding height: have you shot without a grip at all ?
You can try shooting grip-bare, you might like it getting a kick in the bones more. if you get out the grip, due to pressure going in the lower part of the palm, it feels more “kicky”. Like a recoil

See if you get the urge to “fill in” your grip. This is is usually done without noticing. just keep your mind on your grip to see if you do such an adjustment subconciously
trying to find a different position. not completely relaxed and “surrendered”

The above is a guide to feel where your current grip lacks support or definition. Depending on that, you can go with one of the standards. I’d say you stay away from the kit just yet, as you might want to first be sure of what you are looking for. 

As the name explains, this is pretty much your standard grip. It has a very slightly accented lifeline, does not have any thumb placement helpers
and it is not far from what you would get from your stock grip.
The Standard is based on the Spigarelli wooden grip, which is an all-around pretty good base to build upon.
Fits all kinds of palms except the very big ones (you need the K.T.E.E.N.O.S for that kind of palm!)
If your thumb base is very fleshy, you might want to skip to either the Tax Evasion, or the Master too.
Small hands ? The best choice, along with the Master.

The Master is a designer favorite here and has probably gone through the most iterations. Our club shoots mostly Masters. It offers a repeatable
placement with its palm area and accented lifeline ridge and is also awesome for barebow in lower profiles as it offers equal support to the palm
when string walking (thus changing the pressure on highs and lows of the palm).

Big palms, here you go! The K.T.E.E.N.O.S (Greek for B.E.A.S.T) is a flat, wide area to rest your palm. Usually comes flat (no slant) and with a thumb
positioner helper, to make sure you keep your 45 degree angle of your knuckles. Best for recurve, rather than barebow, in the higher profiles,
makes sure you do not cant the bow.

It is not about money! It is about keeping errors away! And the Tax Evasion does exactly this, by providing a very defined lifeline, which, along
on your palm physique, places the hand at the exact same spot for every shot. Still it allows your index and thumb to go into the bow and hug the
riser, allowing to do the “point with the thumb to the target” for perfect bone alignment.

Designed for olympic recurve shooters, the Caerus borrows elements from Hoyt’s great grip designs and adds details that make the hand sit comfortably on one position only.
The throat of the grip is reinforced on the thumb side and skinny on the index finger side, to “fill” the webbing properly and give you a hint on the correct angle, while the palm pressure area is flat at the bottom, curving towards the top.

Conclusion

Big, fleshy, fat hands? Go for K.T.E.E.N.O.S or Tax evasion. Mid sized? Get a Master. Small hands ? You are in the Master/Standard range.
Shooting barebow/stringwalking ? Considering the above, a Master or Tax evasion would help best to even out the difference in pressure when string walking.

Specifics

I have a Gillo riser, what you would suggest for me?

Considering the above, if you feel your current Gillo grip lacks support at the bottom of the palm, you probably want to go for a KTEENOS or Tax Evasion. If you feel that it lacks definition on the top, though, you might want to go for the master.

The Gillo grip has a zero palm slant. 

As the name explains, this is pretty much your standard grip. It has a very slightly accented lifeline, does not have any thumb placement helpers
and it is not far from what you would get from your stock grip.
The Standard is based on the Spigarelli wooden grip, which is an all-around pretty good base to build upon.
Fits all kinds of palms except the very big ones (you need the K.T.E.E.N.O.S for that kind of palm!)
If your thumb base is very fleshy, you might want to skip to either the Tax Evasion, or the Master too.
Small hands ? The best choice, along with the Master.

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