I've looked and I can not find the differences between Boge 510 soft cap cartos and the Boge 510 hard cap cartos. Are the wicking materials the same? Do they both have the little tube going through the middle? I found Boge 510 hard cap cartos on a website that are cheaper than any Boge 510 soft cap cartos that I have ever found. I heard that the hard cap cartos have the caps glued on. Is that true? And if so can you pry them off and refill them just as you would a soft cap carto? Thanks for any info.