"Obsolete" is probably not the best word. I personally stopped playing a 4 string once I became accustomed to a 5 string. It felt "normal" over time. I ended up selling my 4s and played 5s exclusively for at least the past 8 years. Having said this, I traded in 2 of my 5 string Laklands(Skyline models)and yesterday picked up a brand new Fender American Professional Series P bass(4 string). It goes better tonally and esthetically with what my band is currently playing. I could have gotten a 5 string P bass but it wasn't necessary...besides, I already have one...and a beauty at that.(Lakland 55-94 Deluxe in Cherry burst) In case anyone is looking for a really great P bass...the new Fender Professional series are excellent. Definitely worth the money.