Kevin from JustWrite sent me a few of these pens as samples, some weeks ago now, to get my opinion on them before committing (I have three school-aged children, two of whom love playing with fountain pens) - and more recently I've been onto his website to purchase and try out the ultra-slimline Hero pen (haven't inked it up yet).
I'm hoping to put up some reviews over in the pen section - as a 'thank you' to Kevin, and for the benefit of anyone wanting to get a 'feel' for these pens before they buy. For now, I just wanted to say, the Sellner pens especially are AMAZING value for money - especially for a German(?) made pen. They'll take long and short international cartridges, and write wonderfully smoothly. The feed is a 'wick' feed (as is the Pilot VPen, I've discovered!), but that seems to work well. UNBELIEVABLE value for AU$2.75 (plus postage). The Hero pens are made of a less durable plastic, and are designed to take proprietary (short Parker-ending) cartridges - but they come with 4 blue-black cartridges, which is a big plus, and again, are a very smooth writer. Oh, and with a little bit of "encouragement" they'll take a standard international short cartridge happily enough, for those who are not fond of blue-black ink in a delicately-shaded pink or yellow pen...