I have been using my CL260 3d printer (link)[May 07 2017- seems the seller I bought from no longer offers the printer]
You can find a similar printer from other sellers now. For the last 12 months this printer has been my daily driver. While using it I've been making incremental improvements.
I've setup an old laptop running ubuntu and octoprint. This typically can run a raspberry Pi, but I have an old laptop sitting around and I'd have to buy a Pi. Having the convenience of uploading files over wifi from another room might not seem like a huge improvement but it has changed how I use my 3d printer. Being able to pre-heat / print / monitor the print from a local webpage is an amazing upgrade fro my productivity.
You can get octoprint here: https://octoprint.org/
I used these files: (thing:1594362) and Igus Drylin bearings. There is a bit of slack on each bearing, but this disappears when all 4 are installed. I've not noticed any decreases in print resolution but the sound has been reduced from the old brass bearings.
To mount an e3d Lite6 hotend I've used (thing:1822597) This includes areas to mount 2x 40mm part cooling fans. This mount is quite a good design, featuring an integrated hotend fan and a slim design while being easy to print. I really like that the hotend/grove mount locking piece, it tappers up to the bowden tube with ziplock notches to help tidy cables.
I've had a buildTak surface on the printer for the last year. It's worked well, giving great bed adhesion for PETG with temps ~230C/70C for hotend and bed respectively. Recently I've had a few spots which have stuck too well combined with a year of thermal cycles which I'm assuming is making the buildTak slightly more brittle. Upon removing prints I've taken small areas out from the buildTak sheet. For now I've just been avoiding the areas with missing pieces.
Replacement frame parts
About 6 months after I built the printer I found that some of the 3d printed frame pieces had cracked loosening the belts running the gantry. Even though only some of the parts had issues I reprinted all of them in PETG with 0.2mm layers. The new parts are much cleaner looking and much stringer that the original (PLA?) parts.
Finally I've added a spare 8mm rod to the top of the frame and used some odds and ends to create a robust spool holder.
Let me know what Mods you've done on your CL260 or similar 3d printers.