I'll add a spoiler of what I think about the various weapon types in more detail, mind that I practically have 90% of my 3U games in SA and 90% of 4U in CB.
Greatsword: I haven't tried it in MH4U yet. Plays strangely similar to how I use SA (attack - sheathe - attack as much as possible - sheathe). What I don't like is that I can never hit with a maxed charge, monsters move too much and I feel I can get more DPS out of other weapons than the charge combo. The new combo probably changed that, so I'll get a set together later on for the huge elder dragons.
Longsword: It's quite nice, but again, I simply can't use it well. It doesn't fit into my dodging rhythm and I rarely hit with the soul combo finisher. It's unfortunate, because it looks real good.
Sword and Shield: I love it. Mobility, some defence, utility. The low range is bad, but it's actually a good thing against Shagaru Magala tail (I don't hit the wings so much). I used to feel it's weak, but the insane amount of attacks it can get in offsets that. Sometimes I get stuck in an attack and can't dodge or defend but it's not serious.
Dual Blades: Haven't used them in the new version yet. I enjoy the great DPS and mobility though. Mega Dash Juice consumption is problematic, so I prefer to use it against enemies which can be reliably attacked over large periods of time. I don't really like the reliance on items like that though.
Hammer: I used to use it a lot, held back on it now. I use it for enemies who are more vulnerable to impact. KOing is great. It's a bit on the slow side though, so some monsters are hard to hunt with it. Weapon of choice for Qurupeco and Duramboros +similar enemies.
Hunting Horn: Insanely useful, haven't learned how to use it efficiently. I also play solo more often, so it's postponed for now. The speed is a serious issue for me, but otherwise it's always great to have in a team.
Lance: I was a lancer in Tri. Until I couldn't beat the Rathalos with it, but that was more because I was a newbie. Used to feel it has low damage, but it's actually pretty decent. Clumsy to wield, but a great weapon overall. Too slow and defensive for solo play though.
Gunlance: Solves the problem of the lance being slow and not being enough of a damage dealer. The need for a large amount of sharpening is a bother though. I really like to use it to blast some enemies to bits quickly though, so it's fun when farming lower ranks.
Switch Axe: An old friend. I like that it's not unbearably slow (sheathe - attack - sheathe is actually pretty good), can dodge between almost all attacks, great reach and superb damage. All-round great weapon and I like being a generalist. Also has great raw and pretty much no flaws within my style. I can generally get a good rhythm of attacking and dodging with it, which is great. Narga set with Mizar used to be my main set for hunting, I'll probably go for something similar again. Oh, and the Mind's Eye on the sword is awesome. I can't count the amount of times I used it to chop out the Jhen's tusks from above or below.
Charge Blade: I love that it's a powerful, but slightly slower SnS with charge attacks and an axe. The axe has great reach, though some enemies are a pain to hit. I would actually prefer to only have the SnS mode, as that's surprisingly powerful and versatile. The discharges are a bonus, besides being able to KO or deal bonus damage, they also have a Mind's Eye effect on them, which made my Nerscylla farming so much easier.
Insect Glaive: Mixed feelings about this. The damage output seems rather poor and the neopteron seems uselss. People might consider it OP, but just like the longsword, I simply can't adapt to it fast and I can't care enough to try.
Bows: I like the mid-range fighting, though gunner armour makes it pretty dangerous. Overall, I don't use it much, though in some special cases I might, like for Bnahabra farming and such. I find it somewhat boring for solo play though. (The dodging is intesne though!)
Bowguns: I'm grouping them together for a special reason: I almost never use them. I don't find the BGs good for solo play and ammunition management isn't very exciting. Also, monsters don't seem to give so many signs of damage when shot, so they feel weak.
In general, for now I'm using SnS (10% - mainly G. and Sh. Magala farming) and CB (90%). Luckily, I'm good with 'em, though one of the discharge combos for the CB eludes me, which might be a disadvantage, but it's all worked out so far. Hammer for the annoying monsters that bounce cutting. I don't have any exceptional switch axes right now, but I'll probably use it for when my sharpness is insufficient or I need good reach. The rest will probably be held back, though in the end I'll have sets for them anyway, even if I won't ever use them because my efficiency in them drops near 0...
The limited upgrade options are very annoying for the new weapons, that's true, though I guess it helps make people use other types. Not that I need more than 2-3 weapons from one tree.
