Heya!
Didnt read all the replies to this thread... but to answer your questions:
1. Out of all the things I've tried to restore my hair, the best outcome (and probably the most surprising) was with the toplace unit. That is to say Ive tried a big hair club company but the results with toplace were much much better and more realistic (and for much less money)
2. As with attachment, you will have no problem as long as you do the common sense thing and use stronger bonding attachments. I exercise regularly, football, gym etc. What I do is, I use Supertape and UltraHold glue - they are for 4 weeks bond, but I use them only for 2 to 3 weeks. When I detach they are still very strong, but I'd rather feel safe if you know what I mean.
3. As for challenges, yes, hair wearing in my experience comes with its own challenges, but with the right products (which you will have to find for yourself), if I can be honest it takes me much less time than my real hair. It only takes me about 2 hours every 3 weeks (and that is when I detach/ clean/ reattach) and its cause I like to make my time doing it. Rushing through it will most probably make for a bad attachment. You don't want that, if you are like me, too conscious of your appearance. And like I said in the previous point, if you use good products, I dont even worry about the hairline... and I am not just saying. If you look at my previous posts, I was very concerned about this cause I could not get it right. But I didnt give up, continued trying different products till I found the perfect one for me. I glue the hairline, and then apply Hair Spray Gel on it, keeps the glue from seeping down... after 1 week, I usually release the front bit and glue it again just to keep things fresh. It only takes about 5 minutes. So I really think it is not too much high maintenance with the right products. I am pretty sure you spend more time than that everyday to style your normal hair to look 'good'.
4. I kinda disagree with Paul on using 2 units for different purposes. I want to spend as little time as possible on my hair. Having 2 units means you'd have to detach clean and reattach based on your plans. It would drive me insane. I use an All French Lace and SFS front - the undetectable ones... both for gym/swimming/football and for night outs. It base (since its lace) is breathable and you will not have any problems. I am not a good promoter for Poly bases. They are uncomfortable, and leave so much sweat (and ichyness) when you work out. I might be inclined to try out the iLace but I have ordered the same french lace with SFS for now... why change something when you are happy with it?
5. As to cut-ins and styling... I have no idea but I just do it myself. Never found a good stylist with my own real hair (having tried even Toni&Guy and all those famous salons) so... yeah, real hair is forgiving, hair systems not that much. Go slow and diy in my opinion. You won't go wrong. It doesn't have to be PERFECTLY cut to look good.
Just my 2 cents.