I have had problems with keeping temps up with PLA cooling fan on, and really slow heating up to 240c even after PID tuning. Over 240 is probably not fun at all. I then realised that i got the 25w blue lead heater cartridge in my full kit (12V). That is NOT what i expected. I bought the v5 and there was 40w cart. Nothing on the homepage about kits with 25w, and pics show 40w. ONLY the wiki tells me in "whats in the kit" that it is a 25w. This could also perhaps have something to do with the PLA jamming problems some have ( too low temps and problems keeping temps) . I solved mine by drillig the heatbreak, but that was before i realised what heater i had. I had a spare 40w heater with which i get NO heating problems with fan on or off. I have emailed the staff about this. A 25w has really nothing to do in a 3d printer for serious printing.