well I have both, JP6 from 2009 and JP100D from Febr 20th

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I will write my review here after a while , but until then:
-first JP100D is based on the “Ball Family Reserve” Model JP6 and not on the JP as you may already know and we are talking about a price gap of 2000 $ at least, so how rational or fair is to compare them

-I can't talk about the BFR JP6 compared to JP100D cause I have only the JP6
-compared to the JP 6 the quality of the JP100D is very good, but attention to details and craftsmanship is for sure higher on the JP6
- on my JP100D fretwork is very good, paintjob is great, but if you are picky you will still see the a difference for sure compared to a JP
- sound is great for sure , the only thing I've noticed the dynamics thing stated above and that harmonics are not so easy to get on the JP100D as on my JP6 and maybe the sustain is a little lower
- biggest difference in my opinion would be the hardware: nut, pots, switch, tremolo system...the tunning keys look/feel very very much like on the JP
- nut is not compensated and nut slots are not cut deep enough like on the JP - you can easily adjust that with patience
- pots and switch are not high quality for sure but that is a 30 $ investment to have quality ones if you feel the need
- tremolo system: well the tunning stability on this 3 weeks in my opinion is just as good as on my JP. after a good setup, lube on the nut, knife edges, studs tunning stability is similar to my JP. the thing I dislike most is the fact the tremolo arm is not pop in style like the JP. you push it in and it's hold by a screw which if you don't want the arm move in it's pocket 1-2mm before the whole tremolo starts to move you will have tightened pretty hard and then the arm will be stiff and practically a major inconvenient in removing it from picking area after you used the tremolo
- the overall feel of the tremolo is OK but the way the tremolo arm was designed is a major disappointment for me at least. a pop in style would have been heaven. I said the tremolo feel is OK but nowhere as smooth as the JP6 tremolo. this is the biggest difference that you can not easily change it after purchase

- the neck is very comfortable, for me actually I could say that after 3 weeks seems more comfortable the JP6 neck. this is stated to have 42 mm at nut , I measured it and re-measured it , has 41 mm at nut and 42 mm at 1st fret. the JP6 has 43 mm at 1st fret. the the 100 D is a D shape for sure, very thin, but has more shoulders compared to the JP6 which is more of a C to D shape. to me having small hand is very comfortable
- is the JP100D worth the money ? well I will just talk about the US prices

) and the answer is YES. you can buy it between 650 $ - store displayed model mint condition and 829 $ new unboxed
If it had the pop in style tremolo arm maybe I would think twice if I need a JP6 (currently I'm just a home player, no band now) and if it had the whole JP6 tremolo system I would think 100 times if I would spent 3 times more on a JP

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but then again, if they would make them just as the JP6 who would pay 3-4 times the price

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they have a very fair price in US, I wouldn't hesitate to buy one...and as I said I did not hesitate even if I live in Europe and bought it mainly just to have the chance to compare them

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on Saturday I've checked a few ibanez guitars at a local guitar store...and in the same price range they are pure crap , made in indonesia also btw
they can easily be compared with Ibanez premium that's it for sure ...if not actually with Prestige, leaving apart the double locking tremolo systems on those which is very appreciated by many
if it is just a back up guitar and don't wanna spend more money on a JP definitely it's a great choice.
anyway in US you can return the product for a full refund, so I'll go for it before even asking

) as I said I did it already and I live in Europe and the cost with VAT and customs and shipping is almost 50 % more than US price (EU stores sell it for 1745 $!!!) and not regret it