From the replies so far, you can see that there is really no one method that fits all of us. We each have our own preferences and needs and what works for me may not be the best choice for you. This is where an Endocrinologist's or other prescriber's experience is extremely valuable.
Generally speaking, you can think of injections, patches and pellets as somewhat timed release forms of Estradiol, but if the peaks and valleys of your method is too much for you, then the rule is to lower the dose and shorten the interval to get a more steady blood level.
The sublingual method is known for extreme peaks and valleys, but for many of us, myself included, this really presents no problem. It is also worth mentioning that swallowing your tablets whole, does not produce the extreme peaks and valleys, but most of the Estradiol gets metabolized in the liver before it can go anywhere else in the body.
It is good that we have many choices in how we can take our Estradiol.
Take care.