Hi KDan,
I've been playing with it now for a good few days and used about 2kg of filament so far. My initial thinking is it's very well made and one solid frame. All the joints of the frame are not bolted but welded together and then dressed to make one complete unit. The bed is slightly domed I think, with a high spot in the middle of about 0.1mm. However, it's still printing great parts, the best out of all my printers at the moment. All the parts are BIG and I'm getting zero warping / lift etc. It's turning into my go-to machine at the moment. Some parts wouldn't fit on my flash forge dreamer and I was getting lifting on my Dremel 3D40.. mainly because of poor buildtak. So this Z603S is really doing well.
I completely agree about the open frame. It needs enclosing for ABS which is why I'm designing something up. I've already done the sides / front door. Just need to decided what I'm doing for the top. Photos below for you.
I will also be looking at adding auto-bed levelling, filament sensor and removable bed. I really think JG Aurora should make a Z603S Plus unit with these bits added.. market it for about £600 and it would sell like hot cakes! .. lol
I'll be doing a video review soon. But got to say I'm really impressed with it so far.