Hey Pulpy,
Actually, it's for someone elses father - not mine. I'm working on a Captain Canuck figure for my dad.
My apologies for the delay in responding - just saw your Q' today.
In your opinion Blayne, do you think it's worth it, and are you happy with the results first hand?
Yes, and no. If you need an accurate *shape* for the head, it's great, particularly for when you really need to nail a likeness. However, the grain feels exactly like a Sugar Cube. It's... awful, but a side product of the 3D printing process which (I believe) uses different colors of dyed SAND.
If you're careful, you can sand down the worst of it - but be carful when sanding the curving areas near the jaw/ears: Because they have a wood-grain like look/shape to them, sanding too hard, or too much in one direction creates a white blanching effect. I had to rub this one with isopropyl. alcohol to remove the worst of it.
The best approach if you want to use this service is to buy two (it's not that much more expensive) - and sand one down as much as you want until it blanches. Keep the second just in case you mess up. I tried just using Vallejo or other brands to do the base coat color, but it just settled into the piece, and still showed the grain.
To paint the sanded head, use thin layers of Tamiya paint - it's thick enough that after a few layers, it's a nice, smooth/resilient surface. I use their thinner a little bit too with the paint + a good 7+ hours between coats to avoid some layers not fully curing. (For a good example of the layered paint effect, check out the 'Cat the Bounty Hunter' or Blayne v2 customs I have posted here.) If you go too crazy with the paint layering, you'll have to strip (or peel, ugh) it off and start again. A good example of that happening was with my 1st go with ThatsMyFace products here:
The bottom sub-image shows that blanced out version fully painted beside an untouched version from the company (I ordered a few heads, heh).
So - final verdict? I'll be using their services again - but I'm still not looking forward to the sanding. Since my next project will be a figure of my girlfiend, I might just keep it un-sanded so the photo-wrap 3D printing is left intact.

AWESOME what an incredible job ....

Not only is this a cool present because of the subject matter, and the excellent execution, but because it is something you worked so hard on, and it showcases your talents and it's really cool that you can share that with your father!
On a separate note, I've had the that's my face website save in my favourites, and in my firefox tab for month, and I know you've used it several times. In your opinion Blayne, do you think it's worth it, and are you happy with the results first hand? Because from the photos it looks good, but what the situation grain you mentioned having to sand off? Is it that noticeable, and of need of fixing?