They are all a good quality pipe. The Big Gun and R4 will be very close on the power output and weight. Big Gun is rated at 98db and the R4 at 97db, all around very close between those two. Yoshi on the other hand is lighter than the previous two if you go with titanium, but more expensive too. The Yoshi will put out a touch more power at 95db. There are cheaper alternatives to the Yoshi with Aluminum and Stainless constructed pipes as well. Good Luck on your choice.
2000-440ex Stroker--Fan Cooled
Houser +1 A-Arms, Elka Triple rates, Laegers +1 1/4 Swingarm, G-Force Axle w/Durablue Anti-Fade Locknut, 14/36 Gearing, DID X-Ring Chain, C&D Revalved Rear, Maier Silver Plastic, Steel Grey PCed Frame, SPAL Fan, AC Bumper, Pro Armour Footpeg Extensions, Renthal Bars, Yoshimura Full Exhaust, 450R Carb w/ZR's Adaptor, K&N w/o Lid, Powroll 440 Stroker w/stg 3 HC, P&P Head, HD rod, GT Thunder HD Studs, and Timing chain, AMR Monster Coil, 4 Degree Advance Key and a 12oz lighter flywheel. Now at 12.5:1 Compression!
450R Front brake upgrade using 06-up Spindles and 07' hubs.
450R Rear Brake Upgrade
Kenda Knarly XC Radial 21x11x9 Rear Tires
Shorai Lithium Iron Battery
Running E85--Jetting: 70 pilot, 240 main, HRC needle on bottom notch and shimmed.