The advantage of the V15 Type IV stylus over the Type III is that it’s a hyperelliptical (line contact) and so has much more extended contact up the groove walls compared to the Type III elliptical. That means better sound and lower record and stylus wear. The Type IV stylus also has the advantage of the stylus brush, which damps resonance, discharges static, and sweeps dust away from in front of the stylus - dust is a significant cause of record wear, as it’s an abrasive.
So there are quite a few advantages in using a Type IV stylus, compared with a Type III one, although the disadvantage is that it will usually cost more, even as an aftermarket (generic) replacement (not that you’ll find many genuine ones these days, as they are no longer made). Line contact styli may be called Shibata or hyperelliptical (the original Shure name for line contact). LPGear sell what looks like an acceptable replacement
http://www.lpgear.com/product/SHVN45HEL.html at a realistic price.