So I run the alkin which I love fills my scbas with ease. I have a few pcps in the lineup that I use at 300/310b and the scba gets close but I want a full top off. I have the xsciso which is was the better version of the cs3 when it came out that has the little oil coiling feature. It has done great but I think going from 275/280/290 range up to where I want to top of at 300B+ will eventually fail it's alot of work at that pressure. I was thinking of getting the CS4-I for this specific task but was wondering what suggestions you all have or use. Thank you for the info.