Ok here's my take on why I love skin more than lace. This is strictly regarding injected hair, not the v-looping method. And this is with a full head glue bond (which imo is essential for a thin skin system and with lace is much better too:
The first thing is the scalp. It just looks so incredibly real compared to lace. There are no knots. And when you part it anywhere or look at the crown (pics in this thread are not a geat example to be quite honest) the scalp looks slightly lighter in color, just like real scalp does, in comparison to the skin on the face.
And every hair is individually coming out of the base, instead of being tied in groups to a single knot. With the base being translucent it looks like the hairs fade into the hair follicle under the skin. Real scalp skin is translucent at the surface too and looks the same. Single hair injection not only appears realistic but means you get much less bulk than with a lace system. Touching the hair feels light and soft because of this, even at higher densities. If you compare a 75% lace unit to a 75% injected skin unit you will instantly feel how much more natural and light the hair feels on the skin unit.
Hair direction will remain the same as when you bought it and you won't get all those random hairs sticking straight up like with lace units when you've worn it for a few weeks and the knots loosen. You won't get any pull-through to cause itching underneath. You won't have a sticky mesy hairline because for the very front edge you put the glue on the base instead of the scalp, then there is no extra glue out the front. When you part the hair it looks REAL even up as close as your eye can get. I can't express it enough. No more mesh grid pattern. No more awful knots. How many people with really dark hair are tired of knots that simply can't be bleached? And a crown that doesn't look natural?
When you wash your hair, water doesn't get under the base to weaken the glue.
When it's time to clean the glue off the unit it's a real easy task compared to lace. Just wipe on some Goo Gone or Autoglym Tar remover, leave sitting for half an hour, and then wash the glue off with dawn dish soap. Repeat the dish soap part 2 or 3 times until it is really clean. It comes off much easier than with lace. There is no mirror sliding mess to worry about and no glue getting stuck in the holes and in the hair of the lace. I shaved 30 minutes off my clean up time just by switching to skin.
The hot head myth. I don't know what some people mean when they say skin is too hot. I think either they are wearing thick skins or they are not attaching with a full head bond, leaving air and sweat to be trapped and cause heat.
The one and only downside that I see is not easily being able to have a brush forward style with a spiked up hairline. If you want this style it will be hard to get the hair to go straight up or back because the hairs are injected forward (unless you choose all brush back injection). But for me this is no problem as I go with a short spikey style with the front half inch or so brushed forward and to the side. Like this:
And sometimes I do it like this:
I used to wear a spiked up style but that can be restrictive at times like when wearing hats and worrying about getting fluff stuck to the front of the lace, or wearing helmets, or generally having to maintain a flawless hairline at all times. So for me a cool short choppy brushed forward to the side style looks cool and with thin skin life is so much easier.
A good clean lace hairline is still better for those spiked up hairlines but thin skin wins in every other way for me.