I had TIs on my 64 when I first got it. I never really felt that they were right, and tried Chromes as an experiment.
At first the tension alarmed me too - I needed some real truss rod tweaking! However, some observations:
- The tension means I can get the neck really rod straight - and with an action of 1.5mm across the board it plays really really well
- It's more stable throughout the year - seems more balanced
- The tension does let up a bit as they bed in. I use TIs on another bass, and some labellas on another so it isn't just me getting used to them
- After 3 months they dull sufficiently to retain some chime but it's not dominant