I'm not familiar with either brand. Checked out the web site for both. Add-a-grapple is a bucket grapple. Wildcat is a standard grapple. Either choice will require added hydraulics. Either a third function system or extension from your rear hydraulics - if your tractor has this.
There are advantages to both. The add-a-grapple uses and keeps the bucket. The Wildcat eliminates the weight of the bucket and gives added lifting ability.
I have a heavy duty grapple( Land Pride SGC 1560 ) and WR Long third function on my M6040. Since I installed the grapple five years ago - I've never changed back to use my bucket.
I have never heard anybody on TBN say that their choice was wrong or didn't work as they expected.
There are really HD grapples, such as the one I have, and there are lighter grapples. They all have their place and function.
A suggestion - whatever you decide - look for a unit that has grease-able joints. Properly maintained they could extend the grapples useful life.
If you go with a standard grapple - look for a unit that will connect easily with whatever connection system is currently on your FEL.
Check carefully on overall grapple weight vs strength. Extra heavy grapples may not necessarily mean extra strong grapples.
Remember - the heavier the unit you choose - the less you will be able to lift. My Kubota M6040 with grapple.
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