Parker 51 vs Parker IM

Otherwise it's a nice pen, although weighted toward the top (as another reviewer pointed out in a review of the blue/silver version); the Parker Sonnet ballpoint I have is better balanced. Uses twist action and comes filled with a black medium Parker Quinkflow refill.

Combining aluminum with plastic also feels flimsy. I just got the Parker IM in gray and black, every once in a while as I hold on to write, I feel a give on the plastic which I find to be cheap. The Everyman aluminum pens are passable, but just slightly under the weight I would like.

Only works with bottled ink, but even by writing several pages (probably 20 at max) each day, I fill it once a month (or every 2 weeks depending on usage). The MK II model I use is less expensive and plain than the MK V that's around on eBay for around 40 bucks, even though the latter is worth every penny it costs.

This being said, before I keep on splurging on my quest to find the right pen, I figured I also need to consider ink types / cartridges.

I have no real requirements other than a nice, interesting writing experience (either because it's a flex/stub or because it writes beautifully, like a Parker 51, or whatever other reason), but I admit I'll start balking if the price climbs too high unless there's a good justification - I plan on using this pen, so something like a Namiki is out of the question since I'd be terrified to get those pieces of art dirty or drop it or lose it. I don't know what to choose, though, so I'm going to put it out there for opinions.

The Sonnet is intended to be a gift pen covering the low to mid market, but it's so widely counterfeited, including in commercial supply chains, as to be assumed fake until proven otherwise.