These will basically assume you've seen the original Japanese and essentially concentrate on how good or bad the dubs are and whether it comes with cool DVD extras.I know there are "anime snobs" that will only listen to the original Japanese regardless of how good or bad the dub is, there are also idiots who are too stupid to read subtitles and call those that do "weaboos" (news flash, you're watching anime numbnuts!). I sit on the fence, I am not pro sub or pro dub, I'm pro good dub. I enjoy a good dub but I'm too lazy to watch subs over dubs as long as the dubs are passable
With that in mind I think I'm able to judge dubs quite fairly 
Sengoku Basara - Samurai Kings - Got this for my birthday (yesterday, thanks for remembering
), I've seen both season prior to this and I gotta say I was curious as to how well they'd pull it off and to how they'd interpret certain stuff. One of the most iconic scenes in the first episode is Yukimura and Shingen shouting at each other, "Oyakata-sama!", "Yukimura!", "Oyakata-sama!", "Yukimura!", "Oyakata-sama" is translated to "My lordship", which works as both a translation and fitting the mouth flaps. Ontop of which the mighty Johnny Yong Bosch voices Yukimura and pulls it off wonderfully. Those of you who've seen the original (and if you haven't, for shame!) will be well acquainted with Date Masamune's hilarious Engrish, "Get your guns on, yay!" Gotta admit I miss it in the English version 
Onto the good news; the voice cast is awesome and they do a pretty darn good job. I mentioned previously Johnny Yong Bosch (Black ranger, Ichigo, Vash, etc. etc.) voices Yukimura, Reuban Langdon (DMC 3+4 Dante, SF4 Ken, accomplished martial artist and stuntman) is Date Masamune, Vic Mignogna (Edward Elric, Tamaki Suou, Ikkaku Madarame, etc.) as Akechi Mitsuhide and Greg Ayres (Kaoru Hitachiin, Kouta (voyeur), etc.) as Kenshin. Actually an interesting choice is the voice for Sasuke, it's a pretty different take on the character that seems to change his personality a little too. Vic does an excellent job, he usually voices heroes and he's stuck with a real douche of a character to voice
The bad news; this is pretty annoying to me but names are mispronounced pretty badly. Come on guys, this isn't the year 2005, or even 2000, how long have you been in the business now? VAs actually listen to the originals now so why are you pronouncing "Yu-ki-mu-ra" as "Yu-ki-mor-ra" and "Ma-sa-mu-ne" as "Ma-sa-MOO-ne"? I don't expect pronunciations to perfect, just mostly accurate. Despite the annoyances it's still a real joy to watch (and listen).
As for extras there isn't an awful lot but the entire season did only cost me £12.50 (13 episodes on 2 discs). There's a small mini-series on it and textless opening and ending and that's it. I'm one of those people that really like listening to commentaries, not any commentaries just good funny ones. Futurama got me into them, it's like another episode that's informative as well as being funny. So if anime have the odd commentary where the VA have a good chat and share a laugh with each other I like to watch that, sadly this one doesn't have that
Edit: I was wrong, not Reuban Langdon, he must have done the voice for the games prior
