Guess it's time I plug the Aurisonics AS-2's.
They use an entirely digital process, meaning if you have an audiologist take impressions they will be able to offer an exact fit due to scanning in the impressions and using a 3D printer to make them. They also have a special material they coat the tips with so they make a great seal every time and stay in place even when you eat (something that is weird since I have a pair and no hyper-coating, so it's weird eating with them.
They have a 15mm dynamic driver and 2 Balanced Armature tweeters. They are definitely musician grade but are amazing as a normal consumer. I have enjoyed my pair like a kid is to discovering music for the first time. IT's outrageous how great they sound and I have no regrets in my purchase. I have a review in my signature to a review of them.
Of course, besides the hyper-coating, a generic model will be coming out later this year. You may be able to contact Aurisonics about potentially getting on the list of people that are getting the generic model for a few days. They've been going around a lot. Check out Aurisonics' facebook page to see someones reaction to the generic model, they are definitely impressive and can't recommend them enough.
In order not to be biased, people have been enjoying customs for a while. I just happen to have experience with this companies process and products. I have heard UE's generic models and they are very nice. Interesting sound signatures that will suit all types of people.
The thing to be aware of is that each company has its own reputation for it's care and build quality. 1964 Ears, Ultimate Ears, JH Audio, Aurisonics, and a few others in the US have some great responses from purchasers. I wouldn't hesitate or worry about fit or build quality from any of those companies or a few others in the US.
The main rule around here is it's not what you spent on your rig, it's not whether or not you have the ultimate rig you want or not, it's just about a great conversation about what we all enjoy, which I believe is music, and how we get the most out of it. I see the investment into customs as simple. yea, they cost a bunch, but with a removable cable and perfect fit to your ear, why not spend that money for a product you can enjoy for years. If you have the money and are curious, email the companies about their wait time and sound signatures of their products. Make an informed decision then as you will get familiar with their customer service and which product you want.