Hi Noheroicsplease
I am speaking as someone who has been using estradot happily for nearly 11 years so I am biased! Seriously though it is a question of which one you absorb better as well as personal preference. It's not possible to give an exact equivalence but be guided by low medium or high dose - with estrogel I think 1 pump is low, 2 is medium and 4 is high. With patches 50 mcg is the standard medium dose post-menopausal dose given in continuous combined HRT but some women and especially younger women will probably need higher. I actually use 62.5 mcg unofficially - for the past 6 months or more - but most of the time since I started it's been 50 mcg which eliminated all my symptoms and enables me to function normally

(!)
Yes almost all HRT oestrogens are bioidentical except for the PREM ones that come from horse urine. Some of the tabs contain estradiol valerate which is converted to estradiol in the body so counts as bio.
Re consistent flow - the patch will deliver a more consistent dose through your skin although the gel should build up to steady state in the blood system as far as I understand. Some women seem to get a big "hit" soon after applying gel so may experience temporary very high doses which you don't get with the patch. However some women find the patch dose tails off too quickly - although this can be overcome to some extent by increasing the dose and possibly changing the patch every 3 days. With patches it's important to make sure it remains stuck so I have a regular feel, check, and press it down (if necessary) every loo visit.
Many women like the gel because they can adjust the dose more easily but with high doses I imagine it is quite a large amount to spread over your skin - but as a gel user you will know what this is like!
Hurdity x