Agreed SteveD; nothing special, just the standard exhaust pipe and a cheap short megga, with a removable aluminium end cone. Before you or others ask, the sound deadening material

was all lost within the first 30 minutes of running, so all that remained was the perforated sheet metal baffle tube.
Up the main jet to get rid of the 'hole' in the upper rev range and keep the revs below 3 grand in town to reduce the 'symphony' and all was well, but from 80mpg at steady throttle cruising it dropped to 55 - 60mpg.
Alternative 'silencers' as they don't run well with restrictive exhausts are a gutted 'Goldie' that keeps the power mid range (70cm long overall). Mine was cheap and the perforated metal tube rattled inside after 6 months; so out with the hacksaw, empty the rattly bits out and then have it welded up, dress the welds and use matt black 'Sperex', cured in an oven as per can. Some of these bake on insulating coatings might be more robust than 'Sperex' but I haven't gone there.
And the small Supertrapp used for 2stroke and 4stroke off-road bikes:
Supertrapp_Universal_3M_steel_dirtbike. Mine was cheap "old" new stock and required a bracket welded onto the body of the silencer so that the exhaust didn't waggle about. Yet again, the fibreglass wadding lasted no time at all, so there is no core inside the body and just the 'diffuser' discs keeping the 'symphony' muted. 12 discs is OK, but if you pop 18 on that frees up the flow, yet takes the 'crack' off.
I'll keep you posted.
My regards, Bill