It seems that whenever someone has a project to soup up a cheap bass, you get the old "with the cost of the parts, you may as well get the real thing". Sometimes it's true, sometimes it's not. Hey I'm all for saving money. I'm one of the biggest cheapskate GASsers you'll ever meet. But, sometimes a guy doesn't want something that is just like everyone elses. In some ways it's just too easy to slap down $1000 and get a great bass. There is a certain joy and sense of accomplishment to make a cheapo bass play or sound like a more expensive one. I glow when I play my Essex P Bass at a gig, and someone comments me on my nice sound. They'll ask what kind of bass I play, and I tell em it's a bass made in China that I bought for $100. I don't tell them that I put in an aftermarket pickup because I just love the incredulous look they give me. It also makes them think that all the tone must be in my fingers (which it mostly is), not the bass. I'd rather have someone notice my playing over the kind of bass I play. It's just easier to do with a cheapo.
Sometimes parts can be bought cheap, and pickups are some of the easier parts to find on E-bay. Now I hear plenty of people say that you can get the real thing on e-bay for a cheap. But sometimes we don't want to take the time searching, when we can use that time tweaking what we already have. Believe it or not, some of us just like tweaking our basses.
As far as playability is concerned, I have played plenty of expensive basses with a poor setup. Now the construction and materials may be great, but if someone didn't adjust it right it is no more useful to me than a cheapo, other than resale value. Pickups that are not set to a players preferred height, or action that is too high or too low, intonation that is off, a necked that is bowed, uneven frets, or a nut that is improperly cut are more prevalent in a cheapo bass, but it doesn't mean they can't be fixed or that these symptoms can't exist in a more expensive bass. Even with expensive basses, I tweak them until they play right to me. The OLP is not likely to play like a Stingray out of the box. But that doesn't mean that you can't improve it's playability with just a couple of allen wrenches.
Now old KenToby ruffled some feathers by saying he had a REAL stingray. The truth is that it is not a REAL Stingray. It might sound like a real stingray, but it isn't a real one. The headstock logo, 4 bolt neck joint, basswood body, bridge, pickguard, tone controls, pickup and serial number should tell you it's not a real Stingray. Sound on the other hand is subjective. Some of us just hear stuff that others don't. That's why some producers have a magic ear, and others don't. Same reason why some people can tell if their bass lines are off pitch, but not when their singing is off. Some of have hearing loss in certain frequencies. Some of us have different memories or ideas as to what the Stingray sound is. Also, since the consistency of quality of the cheapos can dramtically differ, who's to say that Ken doesn't have one with "mojo" and others have played OLPs that didn't. If the thing sounds like a Stingray to him then it does. If the thing doesn't sound like a Stingray to someone else, then it doesn't. For most people in the audience, it just sounds like a bass.
Tone is in the ear of the behearer.