4mm connectors are a bit small IMO, I prefer either direct soldering or the 6.5mm connectors CC uses. I haven't tried any of the 5, 5.5, or 6mm connectors out there.
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz
I was currently using direct soldering but when I require to pull apart and clean the motor I have to unsolder and then solder back. I was looking at the 6.5mm but alot of people said there overkill and then I noticed that the Tekno motors come with 4mm connectors
from experience the 2.5d would be fine with 4mm, thats what i put on my 1512 3d, they dont get warm and neither do 4mm on the 2.5d i used to run 4mm on my 1515 2.5d and they didnt get warm.... my battery was only rated for what the plugs were so if the plugs started to get hot i knew i was pushing my battery.