Thought I might clarify a few points for you in case there's been a misunderstanding.
You describe Dialog 2 as "a roller ball with the qualities of both roller/fountain". There's two ways I can interpret this:
----Maybe you have gotten the wrong impression and think that this is a bottle-refillable rollerball, similar to the Monteverde One Touch Engage which dropped once upon a time; this pen is not like that, it only takes capless rollerball refills. And, at that, only a particular type of LAMY capless rollerball refill. And, unlike most rollerballs which claim to be compatible only with the refills of their manufacturer, you really can't use anything else without unrealistic amounts of screwing around. Don't buy this pen for the wide variety of inks you'll be able to load it up with - buy this pen for the amazing industrial design, beautiful palladium finish and for the fact that (since LAMY, expensive though they might seem, are generally VASTLY cheaper than anything of the same level fit/finish) you're getting a $600 pen which retails for $155 (it's $300 in shops in Australia, actually) and paying $85-95 for it. I despise LAMY FP inks and refuse to use them, but the D2 is just too good value a pen to quibble over refills.
----Alternatively, maybe you mean that it has the qualities of both a ballpoint (ie: doesn't leak all over your stuff, not a pain in the arse, write in any direction and focus on the words not the handwriting) and a fountain pen (liquid ink that doesn't look awful). In which case, yes, but see my point above about refill compatibility. I love LAMY - my first and second FPs were a LAMY Safari and then a Dialog 3 - but nobody goes to them for their inks. Also, don't bash gel refills until you've tried the Parker-size Visconti gel refills. I use them in my (previously MassDropped) Fellhoelter titanium pen and they are stunningly bright and clear. Wonderful, wonderful inks.
Every time you write more than one sentence about fountain pens you run the risk of coming off as a gigantic, self important, condescending douchebag. It's some sort of law of nature, I suspect. If I've done that here I sincerely apologise, people helping people is all I intend :)