I wanted to post separately so as not to clog up the post. While I do not wear long hair, I have been known to keep it long and attached if I have time, ie a weekend, for a day or so, including sleeping in it. With longer hair there is the issues of tangling and a big mess when waking up in the morning...some things such as a bandanna, skullcap and satin pillow can help.
There is more margin for error for blending as there really isnt much if any, the longer hair stays softer and smoother than if you got very short, because as you go short unless you have short hair injection, the shafts get wider and tend to be a little more stiffer if that makes sense, now I am talking about .5-1 inch, longer isnt so much of a problem, still short hair longer, but not quite as short as the former.
Additionally, with more hair, there is less ability to feel any base, at times I almost would like to go longer, but it just isnt me...feeling the soft long hair is nice, and also its pretty great for temple coverage....one reason, and he can correct me if I am wrong, that BA always has longer styles for the most part...for these reasons.
Now short is fine, but it takes some practice to get it down, meaning more blending, etc...but bed head is less of an issue, tangling is less of an issue, to me the shorter the hair the less likely someone would think wig....easier to manage, etc.
So they both have their pros and cons, hope this provided at least some insight.
I wear my hair a little longer than many in here. I get it 7" and the longest is about 5"-6" when cut. Mine has a light wave as well. I never wore short, but what time you save by not having to blend the back perimeter perfectly you will lose by fishing stray hairs from the front during attachment. I have always had a messy hairstyle so it works for me. When I wake up after sleeping(a satin pillowcase is recommended)it looks like the same bedhead that I have had most of my life. I am not very careful when washing my hair other than the products that I use and I am in the 5th month with this unit and very little shedding. If you are worried about the weight of the unit, I don't even know that it is up there. Use a good adhesive..I still use UH for the most part, but I get a great attachment with CP cream Glue and Tite Grip as well. In the summer I swim in good ole Lake Michigan weekly. You do have more weight on your hair when it is wet so if you have weekened the bond with chemicals or extremely hot water, you may want to let it reset before tugging on it. As Jake said, the bandana comes in handy if you are in the wind or something. It will tangle like real hair, but it is a little more difficult to untangle than hair growing out of your noggin. In summary, if you like the look, the trade off is not that bad. My daily maintenance is anywhere from 2 minutes to 10 depending on washing and such. I have attached a photo from last summer, but my current unit is a bit longer. Go boldly into the 70's.
Zappa, that looks good and I wore a similar style with my first system. From this pic I would say that you might think about lowering your hairline, this was suggested to me as well and it made a big difference.
Is that a full cap system in the second set of pics? I tell ya, every time I get down and cynical about hair loss, all I have to do is come here and find some examples like the ones posted above and I think, "Now what was I worrying about?" So is the hair in back your own? I want a 1970's era Paul McCartney moptop, mullet and all! Preferably it should look like I'm simply a loyal rock fan and not like I'm on my way to a costume party (I think that's a good metric of naturalness when it comes to the more avant garde styles - if you look like a professional impersonator, there's a problem).
For me when the wind blows the wig hair does not move like the hair coming out of the noggin. I do not have this problem w/shorter hair. IMO t/b able to handle longer hair your own side hairs have t/b able to be long, too. For many baldies the weak side hair obviates longer styles, at least as far as I can tell.