People say that absorption time is slower with injectable orals. I haven't seen any studies, but it feels that way. I just do one injection daily with injectable orals compared to spacing the dose out through the day.
Injectables have a protracted effect for sure. But it depends on carrier, whether a solution or suspension, mg per ml, maybe even whether the hormone is micronized or not etc. The suspensions tend to crytallize at the injection site. I mean the Spanish Winstrol is called Winstrol Depot; supposed to have effects for 2 weeks going by memory. And the test suspensions administered to animals are also given every couple of weeks.
That said, for even levels I'd take them every day because there's bound to be a huge peak quickly with a longer tail of low activity.