TWSBI’s pens are great, flat across the board. They serve as an excellent intro point to the fountain pen scene for many people, given the excellent quality at an affordable price – heck, the Eco name outright stands for economical. So what’s TWSBI’s highest-end offering like, and how do their rarer nibs, like the stub, handle? I was wicked curious.

The 580 ALR, which I bought for $74 on JetPens.com, is arguably the flagship model of the TWSBI lineup, although their vacuum fillers are also in the running. While not in the class of truly oversized pens I have a preference for, it is relatively thick; I measured the barrel at 15mm around, and it feels great in my aching, banged-up hand. It’s also well-balanced and holds up well to long writing sessions.

There’s a small step down to the grip, with a textured aluminum grip in the ALR model – I figure the R stands for ribbed. I’m not an actual fan here; the ribbing detracts from the look of the pen in my view, and I would probably just get the AL model if I was going to buy it all over again. Moreover, the aluminum trim isn’t a particularly large difference in the look, and the nicket version I got is actually a bit discordant with the rest of the TWSBI design – given the 17 dollar increase in price for the aluminum trim, I’d be very tempted to go with the plainer Diamond 580 next time and save the cash.

The 580ALR stays true to the the signature TWSBI demonstrator look, with a clear barrel featuring a pretty cool, twisting facet effect. With the right ink, like the Colorverse Blue Dragon I’ve been keeping it inked with, it’s really slick looking. There’s no converter involved; you fill the barrel directly with a piston mechanism controlled by a know at the end of the pen. It’s a smooth and solid system, although flushing the pen to change colors can take quite a bit of time and effort to get an uncontaminated reset.

This filling mechanism does make posting the pen a bit of a non-starter. While technically possible, twisting the filling mechanism is definitely possible in the process, and may result in some unexpected drips and drops. Posting the cap also unbalances the pen a bit, which is unfortunate. It doesn’t bother me much as I don’t mind leaving caps north of my notebook when writing, but that may be an issue in some circumstances or for some people.

It’s a TWSBI, so you already know it holds a lot of ink; it’s 1.5ml on the stat sheets out there. I didn’t test this out myself; all I know is that I’ve owned it for months, used it a ton, and only filled it twice. It definitely works exceptionally well as an active-duty, long-format pen.

But how’s it write? That’s the only thing that really matter, write? The 1.1mm stub nib is so smooth it almost freaks me out – it feels like writing on hot glass with a stick of butter even on junk paper – and I freakin’ love it. Note that I’ve always been a big fan of a virtually frictionless writing experience and that’s what drew me to fountain pens in the first place, but can admit that may not be what folks who enjoy a bit of feedback are looking for.

It’s also worth noting that TWSBI sells replacement nib units for the 580s, which screw on and off easily, for around 24 bucks most places. It’s a good bit of added value for people that may want to experiment with different nibs, but not futz with a complete nib swap, tuning, and all that jazz.

That strident adoration of the writing experience said, the nib I got is prone to hard starts occasionally, and will skip on the upward curve of descenders sometimes too. Looking at it through a loupe, it may have the barest touch of baby’s bottom, but it’s so slight that I’m not even completely sure about it, and can’t really fault TWSBI’s QC on this. It hasn’t been a deal-breaker in any way, or even dampened my enthusiasm for the pen.

I can strongly recommend this pen for anyone looking to take a step up from a starter pen, for absolute sure, although I would definitely consider the base Diamond 580 model as the trim isn’t a big difference for a nearly 33% increase in price.