He ought to be far stronger than his EoZ self, seeing as how his SSJ self was implied to be above Base Goku during the Lood fight and he was able to kill someone who Goku found some trouble in. I'd say his base self would be just below Pure Boo's level via scaling and his SSJ self would be in a fairly median range between Post Rosat Gotenks' base and SSJ selves.
If I recall correctly, in the last episode of the Z anime Goku tells Goten and Trunks to keep training hard and they agreed, so I'd say they're well above their EoZ selves. They could've started slacking in the last of the 5 years between EoZ and BoGT and still be considered slackers.