I'm happy with mine, I forget it's threadless and for a tenner it's not too bad although some people will say buy cheap buy twice but I think it's a decent product. Once mine was installed with enough grease and torque I haven't had an issue with it (over 1.5 years commuting in edinburgh) I expect the Velo orange will work out to be even more reliable with the expanding cups but I am happy with mine (especially for ten pounds). If you buy the tools and grease as well it will still work out cheaper than the velo orange one and you can always fix it yourself if it ever goes wrong. One issue I can see would be the standard of your cranks square taper, is it ISO or JIS as the threadless bottom brackets only cater for JIS square taper.
As for retapping I couldn't say, hopefully someone else can come along and give advice.
I'm happy with mine, I forget it's threadless and for a tenner it's not too bad although some people will say buy cheap buy twice but I think it's a decent product. Once mine was installed with enough grease and torque I haven't had an issue with it (over 1.5 years commuting in edinburgh) I expect the Velo orange will work out to be even more reliable with the expanding cups but I am happy with mine (especially for ten pounds). If you buy the tools and grease as well it will still work out cheaper than the velo orange one and you can always fix it yourself if it ever goes wrong. One issue I can see would be the standard of your cranks square taper, is it ISO or JIS as the threadless bottom brackets only cater for JIS square taper.
As for retapping I couldn't say, hopefully someone else can come along and give advice.