I know why Corsair made this move, it was to answer coolers like the NZXT Kraken coolers, but was the effort really worth it in the end? It depends on what sort of plans you have for this unit in my eyes. If you are just getting it to replace the stock cooling solution, or maybe apply a mild overclock, and are looking for silence, this is the perfect solution, as it is the most silent sealed AIO on the market currently. Since I like to push my hardware a bit more than the average guy, I would have taken some more fan noise for better performance out of this cooler. I mean the Performer beat it, and it's essentially the same head unit with a different radiator, and with this H90, I do believe all of the complaints of loud fans have won over in this round.
Ever since this AIOs with the round head units went to the locking plates for the top bits of hardware, mounting has become very simple - not like the old days of twisting things one handed and trying to screw it in at the same time. These days, the installation is so simple that you really have to not be paying attention to screw things up. Even if the images aren't as descriptive as you would like them to be, the way the parts are all labeled, again making things fairly fool proof. On the other end of the unit, it isn't that tough to remove a chassis fan and install the radiator, as long as you take your time, install all the screws a little first before tightening any of them - even here you should have no issues. At this point the H90 has a lot going for it, it is the quietest of the bunch, it's simple to install, beats the pants off of the stock coolers, and removes a ton of weight from the socket versus an equal performing tower cooler. There are just some things that are holding it back.
Once we look at things from a price versus performance aspect, the glitz and glamour of the larger and quieter 140mm solution starts to fade as you realize you could get better performance for much cheaper. In fact, while the H90 is selling for $99.99, or even the $89.99 pricing with the Newegg code at the time of writing, the Tt unit is selling for $79.99 and if you like rebates, it can be had for around $65. Saying that this unit comes with a high static pressure fan, and seeing that this fan was capable of 94 CFM, I had higher hopes for this cooler, but in this case silence wins out over performance with the Hydro Series H90.
My real issue at this point is how to award it, as it does well, but not well enough. Cost is also a bit much for the thermal results in my opinion, and it is stripped of any cool features like the LINK or extra fan headers, or anything really to demand this sort of a price tag. If I were you, I would wait a bit and see if prices drop, or wait and see if the H110 I also received is any better for your needs.