Although i think that this thread lacks a certain.... point... because you simply can't compare the two voices, i wanna throw in my opinion
I usually play the femShep and i really like 95% of the lines. Sometimes i'd wish that the dialogs under fire would reflect the stress a bit more. Like when Shep is talking to Reegar and the Geth are firing at them. Reegar sounds really awesome and stressed, Shep does not... There are other situations too where i thought that a bit more panic or stress would have been adequate. But maybe there's a reason for the generally rather sterile emotion in the voice. Something like Shepard being "in control" all the time or too emotional voices can be annoying or whatever. It's not that bad, really, just something i'd handle differently if i were in charge

I agree that femSheps lines with Jacob are cringeworthy, especially if you don't date him at all.
Her lines with Tali are very warm and motherly, same with Miranda on her loyalty mission. I like that, even if it's actually a military operation and the commander should not get too close like this to people (s)he's about to throw at the enemy, but damn, I like to get close to the squadmates that i care for
So, about the maleShep. I just started my first career, just to be able to finally date the only LI that i care fore (I was really really shocked and annoyed when i found out that bioware didn't let me date that LI as femShep... i mean, i have played sooo many rpg's where the game didn't even "know" what gender i picked, or at least hardly cared. But this seems to be the "prize" for high-budget production. It's not always a good thing hehe anyway). After some hours i got a bit used to his voice. I don't see much difference between ME1 and ME2, i only see that they improved the facial animations a lot, which helps the dialogs. But if femShep is "cool" under pressure, than maleShep is cold... I like his voice and it's ok when gathers information and such. But everything that is uttered on the battlefield is just not believable ("we...have... been... spotted..."). Not sure if there is a directing problem or if the actor didn't imagine the situation vividly enough, but it just doesn't fit the circumstances at all. I wonder if he plays the game

Anyway, as i said, generally i like the voice and mostly it's nice listing to him.
Apart from the voices, playing maleShep the first time makes me realize that femShep is not so well implemented as the male one. The game has definitely been written for the guy first and then the girl has been added. Many NPC's react much more natural to the maleShep and stuff like Gianna etc. is much more interesting for the maleShep. The LI's, Liara, Kelly and everything seem to be male centered as well.
FemShep is not bad... not at all... i just can't help noticing that it occasionally feels forced to play a woman in this game.