Recently, I'm coming to feel the burden on my shoulder, it makes me so annoyed.
As of that, I've considered replacing the hardware (keyboard).
I've searched for a new gear candidate to resolve the above issue with the following conditions:
- MUST: Needs trackpoint (because I'm using ThinkPad Keyboard with TrackPoint so long, I'm afraid to work without it)
- MUST: Separate keyboard (split keyboard) to be ergonomic to reduce the burden on my shoulder.
- SHOULD: Upstream publishes products in a form of source code (I prefer more "free" products)
As a result, Ultimate Hacking Keyboard  seems that it is the best solution for me because UHK implements trackpoint, split keyboard feature, and upstream publishes firmware as MIT-like license. 
It seems the best solution but it costs me more budget unexpectedly (weaker YEN contrast to USD makes it a worse situation). so I've asked about reimbursement  for Debian project.
Fortunately, reimbursement request is approved and processed by SPI , even though there is a troublesome with the paperwork (it's my fault) , I could get a new gear - Ultimate Hacking Keyboard. (Note that reimbursement does not cover all of costs - import tax fee, and so on, but it helps a lot)
Here is the first impression:
- Even though the silent red switch, it may be a bit noisy, but it is acceptable.
- TrackPoint module may not be so useful as I expected, it may be better to use mod layer or mini trackball with key cluster module. This is because it is not an appropriate position for me that trackpoint module must be attached to left on N, Space key. (left to H key is better position for me)
- Remapping configuration tool is awesome. but need to try to find my "best" assignment furthermore.
- It is hard to replace keycaps because of a special keycap width (bit shorter keycap design exists)
- It takes about a few weeks to get used to new gear.
- The curled code is a bit shorter than I expected, so it should be replaced with a longer one.
Anyway, UHK is an awesome product and it is worth to recommend you.