Harry,

As David pointed out, I am building a Yellow F-4.....and loving it.
I have built quite a few Yellow kits, and am familiar with thier construction philosophy, so it is going together fairly easily, but that being said, they are rather simple to build anyway.
As far as any flaws with the kit.....none so far as I can find. It can be built as the instructions state with no mods, and you'll have a great flier.
This is actually my second YA F-4. The first I build many years ago, and lost when I got dumb thumbs in a low inverted pass. It was built as a one piece aircraft, wings not removeable, with flaps. It flew like a dream. Only 'bad tendancy' it had was it seemed to want to over rotate on t/o. Once I got on the learning curve, it was never a problem. Landings are slow, stable, and totally predictable. No suprises there.
The one I am currently building has scale ailerons, no flaps, and removeable wing. I really don't see the need to add flaps when building this as a ducted fan, as I am, so I left them out. I did cut out the flaps, and doweled them in place....just in case I decide to fit the flaps later. If you are going to turbinize this bird, I would install flaps...they will be helpful to slow it down with the added weight.

I have no experience with the JHH F4, so I can't speak for it. I do know that the Yellow is a nice, easy build, and I am sure you will enjoy it as much as I have. If you have any questions, please let me know.

Currently, all my flying surfaces are glassed, primered, and waiting for wetsanding. I installed the inlets last night. Moving on to the nose gear bulkhead today. Almost done.
I will post some more pics once my camera charges.

Best regards,
Jeff