I have a sr 305 and a 505. The 305 was my first Ibanez bass and I was really impressed on the quality vs. the cost. It's maple neck has a nice feel and I really enjoy the sound, something like a thicker growly jazz. While impressive, the 505 really was a step up.
The 505 has a darker sound, but it really has a cool sound once you get it dialed in. I like the sound of the split coil mk1's with the soap bar covers, it the pre amp I'm not a fan of. I find dialing the treble back, boosting the mids and a touch of bass gives it a nice sound that sits very well in the mix. The string spacing is a little tight, and it's not set up well for slapping, due to the placement of the neck pickup, but really shines playing finger style, which is mostly how I play.
The neck feels slim, and is very fast playing for me. There are no balance issues, and I had little issues with the neck moving while I used this as a secondary bass touring. These basses fit me ergonomically, and are very comfortable to play. I suffer from carpal tunnel, and will switch to this bass when my hands get to hurting. It helps. The basses are 34" scale where I prefer a 35" scale, so they feel a little small to me, fast and nimble.
There were issues with the design of the bridge on earlier sr models, but that has been addressed by the company, where the effected area has been beefed up. Ibby was replacing the defective bridges and taking care of their customers. If that isn't a sign of excellence in customer service, I don't know what is. So while this isn't my first choice in basses, I do find myself playing the 505 quite often, it feels like a broken in pair of jeans that fit me well.
For the money, these basses are an amazing value, especially if you buy used. Even though they are not built in Japan, they are built under the specs Ibanez is placing on these basses, and their quality control is superb. Little innovative things, such as the the sliding truss rod cover (so you don't have to take it off) the battery box on the back, or the bridge with a single screw for setting action or the strings that don't go through the bridge, making it fast to change the strings, make it easy for the gigging musician to do quick fixes and maintenance on these basses. I had a bone nut put on mine, but that is simply because I prefer how bone makes the bass sound. I had no issues with either the tuners or how they went into the nut. Like I said, these are great basses for the money. I'd be hard pressed to find another company that puts as much into their basses for the price they charge for them.