I've had 2 different manual converted racks in my car, both used on track with 225/50/15 R's. One was a 17.4:1 rack and I didn't weld the pinion shaft, the other one is a 15.2:1 with the welded rack, pretty much an FD Maval rack and I love it. It gives much better on center feel due to the solid pinion shaft, where the other one had some give to it. The reactions are just that much faster compared to the previous rack. It's definetely worth going the extra mile and getting it welded.

For me the effort's not a big deal and I don't find it tiring, but I'm a big guy. I'd generally agree with others though, that with lots of grip and speed, or with long stints behind the wheel, PS would be preferable, otherwise it's personal choice.