Injectables will usually give much higher levels of estradiol (close to ovulation/mid-cycle and early pregnancy levels) and a ratio of estradiol:estrone similar to that seen in genetic premenopausal women. SHBG and all other liver enzymes, functions will be much less affected so that DVT, pulmonary embolism risks do not increase in contrast to orals where risk is very slightly increased on bio-identicals. Levels will peak the first 2 days and then gradually decline the next few days. It's usually best to inject every 7 days (to avoid pms symptoms) as levels will become too low thereafter but it depends on the person. Some need to inject sooner, some do fine on 10-14 days at most.
So, overall, more convenient...more estradiol, more natural as it goes directly into blood, no effect on liver parameters.