To both, I would say "Absolutely!!".
Why weightlifting shoes are the best thing since sliced bread for anyone using weights:
If you have never worn lifting shoes and regularly use free weights, a good pair of shoes will easily increase your max by 5-10kg or 10-22lbs. This is because weightlifting shoes have a hard, less compressible sole. A good shoe also has a well constructed leather upper that will support your foot with radial and tangentially compressive forces.
The hard sole allows you to efficiently transfer force to the floor. So, whether you're doing a deadlift, snatch, or squat, you want all of your hard Work or energy transmitted to the floor. A soft, squishy rubber sole will waste your Energy. A typical sneaker sole will actually act as a damper, sucking the energy out of your lift.
Think of your lift like thrust out of a rocket. You lift the weight up by as an equal and opposite reaction from pushing against the floor. Again, visualize it like thrust coming out of a rocket- a rocket explodes upward into the sky by shoving expanded gasses out a nozzle which then push against the surface or gasses outside the exhuast nozzle, shooting the rocket upward.
The upper gives support to the structure of your foot. One should not lift bear foot as your foot will spread out and flatten during heavy reps (not good for arches!!). Sure, you can find photos and video's of World champs showing-off by lifting in a pair of sandals or no shoes. And, this is not something they do day-after-day or at competitions, winning Olympic Golds and breaking world records.
Most importantly - SAFETY! A good pair of shoes will prevent lateral rocking, protecting your ankles. A well contructed shoe will keep you more stable and in control of your lifts.
Try lifting a few reps in a pair of sneakers, then repeat the same reps in a pair of lifting shoes. It's night and day. Its like driving a Hyundai Accent then jumping into a BMW M3.
For high quality, shoes designed for both men and women by expert coaches and lifters, go here: www.ristosports.com .
A good bar spins. A good bar oscillates. Both qualities prevent wrist injuries. Bushings are no where near the same as needle bearings. From working in the jet engine business, I can tell you that bearings are an art form in there own. Ford focus is to Ford mustang as Bushing bar is to needle bearing bar.
By the way, Risto shoes are made of leather with a wooden sole. We do this purposely as both the leather and wood will, overtime, form to your foot and stance. We do not use plastic or vinyl uppers, as plastic does not break-in, it doesn't mold to your foot anywhere near as well as leather. Leather is more expensive too. We do not use a plastic sole as hard plastic stays in the same mold from which it came. We are all individuals and need a shoe that will mold into something a little but like ourselves. Wood is hard, yet flexible and will form to our stance over time.