My experience is that resin BFG's are very brittle and will easily break if dropped or otherwise treated anything with kid gloves. I had a resin DC-15LR and will never own another resin job again.
SciFire (buy only from Lewis or Nathan) hold up remarkably over time. I've had mine for about 4 years now, and do the drop test in front of others w/no issues. They are priced very reasonably and now come with all the DLT-19 goodies, e.g. disk, feed tray, and t-racks.
Cushman's Lewis Guns I think more readily lend themselves to looking good, and while great for parades, etc. and remarkably light, won't ever be quite as detailed as SciFire.
My $.02...