@elchamaco - I admit to being biased, I never used Split View by choice and always hated it. I hated the reduced screen real estate for editing. I hated that it never worked properly, that too often it would for instance jump the cursor right to the bottom of the document. What point is there in a synchronised view if it doesn't actually synchronise correctly? Clicking into the other split to get it to synchronise would cause the underlying content to be saved, which reformatted it, so you lost your exact place in both views jumping around, significantly so if it was a large paragraph you were editing. And you had all the well formed stuff interfering from losing focus as well. It was clunky and awful imo. It wasn't me that removed it btw, but I fully support the decision that was made to do so.
So what exactly is the attraction to Split View for you? Is it to see the effect of changes to Book View as you typed them in Code View? Or was it the other way around, of seeing what was generated in Code View by making changes in Book View? Which of those was the "critical I must have it" thing that attracted you to Split View? We have a few ideas we are kicking around that may one day appear in a future release, I am just curious whether they would gel with what feature of Sigil you *actually* used Split View for.
In 0.5.9xx you can double click on the tab heading or hit F2 to quickly flick between CV/BV, and caret positioning will consistently work to show the matching place in the document.
I agree Sigil 0.5.3 has some serious issues, but Sigil 0.4.2 has some equally serious ones - it's propensity to lose content when merging being the most critical I suffered from (hard to spot unless you double check your merged document afterwards every time). That one alone became a showstopper for me - nothing worse than finding chapter nine is the next one available after chapter one when you go to read that book 3 months later.
As others have posted, the enhancements and stability in 0.5.905 or later allow editing to be done in a fraction of the time it used to take without the same problems of losing content, but of course you are free to use whichever version you choose
