Ooo… very good question, worthy of its own forum thread. But I’ll try and keep it in relation to Genn.
From what I’ve gathered, the “pros” and “cons” of the worgen curse vary depending on the lifestyle you’re attempting to lead, and what you were before. A hobo for example may revel in this newfound power, while a businessman may loath becoming so bestial. For Genn, it seems to be something in between. Ironically being a homeless aristocrat himself.
Pros
Resistance to Undeath - Thanks to the worgen curse, Genn and the Gilneas are resistant to conventional forms of undeath, meaning Sylvanas, zombie viruses, etc. The Lich King is far stronger, and can make worgen Deathknights, but he’s not the one bombing/burning cities, spreading plague, and raising people. Anymore.
Affinity for Nature - For the same reasons, thanks to the curse’s connection to two nature deities (Elune and Goldrinn), worgen are capable of becoming druids. Druids that can take the shape of “Inconspicuous Bears” to spy on the Forsaken in Silverpine.
Enhanced Senses - Noted especially in Curse of the Worgen, Wolfheart, and Lord of his Pack, the worgen are able to smell, hear, and even see far better than ever before. What is more, Genn in Wolfheart says worgen have the ability to sense auras, where humans cannot.
Physical Prowess - Worgen are granted the agility and speed to rival that of the Kaldorei (Wolfheart). When taking to all fours, they can keep up with any horse, saber, or mechastrider (WoW website). They can leap over walls, climb buildings, and tear a man in two with just their claws (Curse of the Worgen). Even Genn Greymane, who’s going on 70 or so, is capable of far more than even the most youthful of humans.
Cons
Rage - I don’t consider most of these as “cons”, but for someone attempting to live as a human again, they would most definately get in the way. Curse of the Worgen describes worgen as “juggernauts of rage”, who will shift into worgen form if driven to anger. This can be treated by any number of anger-suppressing medications and supplements, but must always be managed, harnessed, unleashed, or suppressed. Rage itself is a very big part of Genn’s character, and seemed to be harnessed and focused on thwarting Sylvnasas.
Predatory Instinct - The same applies to lupine instinct. Wolfheart exemplifies this far better than the other sources, with the Gilneans learning to embrace their new role as predators. Genn and his Gilnean guards hunt in Teldrassil on all fours, and feel the need to run and hunt when they take worgen form. For an aristocrat attempting to return to the Gilnean nobleman’s lifestyle, the urge to chase the neighbor’s siamese cat would definately be seen as a “curse”.
Survival Instinct - This “fight or flight” instinct can be good, but also has the potential to surge into overdrive, causing The Mindless State. Driven by fear, despair, stress, or other forms of trauma, a worgen has the potential to fall into a wild state of panic, known as the Mindless State. The most notable examples are those bitten in the Starter Zone, the player character, Mardigan, and Sven Yorgen. All of which are bitten during or after highly traumatic events, and are treated with medication and therapy. Genn too fears falling into the mindless state (War Crimes), but seems to be doing well so far.
Appearance - Worgen are kinda ugly. Especially with the current models. If you’re attempting to live as a human, in human society, you’d want to keep your worgen form unseen. No one wants you scaring their children, and no one wants that ugly mug at a banquet. For the reasons above, keeping up this masquerade would become quite stressful. Even Genn keeps to human form while in Stormwind, even though in Wolfheart it says he’s come to prefer his worgen form.
Wolfsbane - The poisonous purple flower is noted at least three times in the game as being deadly to worgen. First in Northrend, when the villagers tell you (who isn’t a worgen) to go remove the weeds. Second in the Silverpine Forest questline, when Deathstalker Belmont has you go pick Wolfsbane in Gilneas for use against the worgen. And third, used by the newly undead Lord Godfrey, to shoot and kill Gilneans for Sylvanas. Presumably, wolfsbane isn’t as harmful to other races, making Wolfsbane a worgen’s weakness.
In my opinion, whether it’s considered a curse or a gift is up to the character, their perspective, and what life they’re attempting to lead. Many Gilneans call it a curse, while those that embrace it in Silverpine and Duskwood go so far as to call it “the Purity”.
How well they can master the curse also seems dependent on how they received it, and how well. The Gilneas Starter Zone shows us Gilneans bitten against their will, in a very horrific experience, and turning Mindless because of it. Meanwhile in Curse of the Worgen and Dark Riders, we see humans being bitten and turned willingly in a calm experience, and are able to control themselves and even use human form afterwards. Genn was turned in a worgen-hunting accident, and was somehow able to manage and hide it, possibly for years before the Kaldorei even arrived.