First, in interest of full-disclosure
, I bought my first replica ever from Jackson and he is responsible for my current obsession with the 44mm Luminor series - oh, and one 47mm 127. I bought an "homage" 177H with tobacco dial from him, and loved it. I guess I was lucky, or just did a ton of research, with my first purchase, because his titanium cased watches are a bargain for the money.
A few PAMs later, with only one disappointment, I acquired a DSN 240 titanium watch and am very happy with it as well. I now own two DSN watches, and I'm looking to buy a third. With a DSN purchase (an additional couple hundred bucks), you'll get a much better and accurate "branded" dial, supposedly a higher quality movement, better sapphire crystal, quality controlled assembly with pressure testing to 50ATM, much better lume, and an all-round more solid feeling rep. Although, he doesn't accept PayPal, he does take WesterUnion - which can be sent online for a premium fee.
I have never owned a D4M watch, so I can't comment on them myself. But most members seem to only have positive things to say about them
He's also much easier to communicate with than Davidsen.
An interesting thing to note, is the asian 6497 movements in Jackson's PAM "homages". They seem to be identical to those included in most 111H/177H reps, including "faux" swan neck, just without the "Officine Panerai" decal. It also looks like they have the H3/tall canon pinion already installed - the two that I've taken apart anyway. And he sells these for $30 delivered.
As for the comparison of JTse to D4M, they are two different offerings. Jackson's watches are "homages" and do not have any "Panerai" brandings on the case backs, dials or movements. To get more information on Daytona4Me's watches, you should email him - don't bother trying to send a PM.