Chris Clarke G3SQU
The uBITx is never going to be a serious CW contest rig, but I imagine you are not expecting that.
I only operate CW, never more than 20W. Having installed the KD8KEC v1.061 firmware to deal with keying issues, and when combined with a good audio filter, I am very happy operating CW with the uBITx. I am straight key only so it would be good to hear from some paddle-key operators. I use a W3NQN passive LC audio CW filter built from a kit many years ago and sadly not available at present, but there are now many analogue and digital filter options out there to try. I am about to try the SOTAbeams Laserbeam digital audio filter, which comes with great reviews.
When I first assembled my uBITx I reported to my local club that it wasn't a viable CW rig. However, I now enjoy CW operating with my upgraded uBITx, especially as I've been able to customise the software. Last weekend I spent some time working CW in the YU and MM DX contests on the 40m and 20m bands (with my NorCal Doublet antenna). Whilst 47 contacts from on-off operating over the 2 days doesn't break any records, I had an enjoyable time hunting them down when I did go on the air. Significantly, I don't think I'd have done any better with my TenTec 579 (a nice very analog CW rig) running QRP and I much prefer operating the uBITx rather than my YouKits EK-1B or IC-703 QRP rigs because of the customisation I've been able to achieve.
The great strength of the uBITx is that provides a really good basis for experimentation and development, as well as operation, at a bargain price and I'm finding it is a real education when allied to all the support you can get from this Group. It is a true ham's rig and is fine for CW, with an audio filter, once the stock firmware has been upgraded. I am also very happy that I've had an introduction to programming the Arduino, something I'd been thinking about for years but had never taken the step.
Hope this helps.