The build time for the SE 5-way is 3 months, it's an extremely complex design and with a sound signature closer to that of the K10 than the 5S (judging by reviews and descriptions).
I find my acrylic customs to be perfectly comfortable. Once you get a proper fit, the CIEMs just disappear when you insert them. I only feel the cables and I wear my CIEMs for 6-8 hours at a time.
This isn't entirely true. I'm probably one of the newer SE5 owners and my set only took a few weeks to build. Just like every other CIEM company, I think it depends on the flow of business. Also, while I do find the SE5 to be more neutral than the 8.A, I wouldn't consider it a neutral sound at all.