Playing the Guild D55 is like a dream. It's got one of the most fluid acoustic guitar necks that I've played, which is saying a lot as I've had my hands on a high number of different acoustic guitars over the years. The guitar is about the standard size and weight that you would expect from a dreadnought guitar. I've never felt that it was hard to play anywhere along the neck of the guitar, except for the upper most notes, which can be hard to reach on any acoustic guitar. Achieving a nice sound from the D55 isn't hard for those that can play - if you do your job rest assured that this will take care of the rest!
The Guild D55 acoustic guitar isn't too bright like a lot acoustic guitars, as it has a very well rounded tone. It has the full sound that you'd expect from a dreadnought and then some. While it isn't too bright, it still cuts through very well and I believe that it would fit in with any genre of music that you would want to use an acoustic guitar on. I've never used this guitar on the stage, but inside of the recording studio I've never had an instance where I wasn't happy with the end product in terms of tone that I got from the guitar...
I honestly can't say a bad thing about the Guild D55. In the times that I have used it for recording it has been an absolute pleasure to work with. The guitar is built extremely well, and Guild is a company that I wholeheartedly trust as most of the guitars they make are of very high quality. Of course with top tier quality comes top tier price, so you should know that you're spending a pretty penny for the D55. Having said this, if you're looking for a go to acoustic guitar for recording or shows that you can rely on to give you a great sound day in and day out, the D55 will do that for you. While definitely a large investment, I would recommend the Guild D55 to anyone looking for a great acoustic guitar.