I pronounce it like it's spelled...it has a romantic 'i' because it's a f&^$% 'i'. Like the vowel sounds in 'eat', 'feel', 'meat', 'petit', etc. イ. To all sensible people, in a basic word like Vista, that's the default pronunciation of the character 'i'.
I also pronounce the last vowel instead of centralizing it to the disgusting, lazy, germanic 'uh' sound as in 'mud'. Why do average english speakers just decide that certain vowels aren't important? Like practically all trailing vowels. I don't think the trailing 'e' as on the end of はじめまして for example, even exists in english, english speakers are just too good to pronounce vowels on the ends of words, I guess.
And the english 'A' as in 'cat', hat, mad, tally the way american english speakers say them. What makes that so damn attractive? I mean in most languages, even sensible langages that use the roman alphabet, it doesn't even seem to exist. Why do english speakers like it better than the sensible 'a' that words like 'cafe' come with?
And I can't think of a single word in english that contains the plain romantic 'o' vowel. None. It always turns into a smeared dipthong across 'ou'. Why is it somehow more attractive, or easior, to be MORE complicated?
I hope to one day understand what causes american english speakers to randomly assign one of their 13 random and transcendent vowel sounds to unfamililar words.
And absolutely every person that has attempted to communicate their pronunciation through some kind of conventionalized spelling fails. Don't you understand that no matter how you spell it, unless you use a locked in script or IPA, people are going to read the vowel differently depending on their linguistic background? It really blows my mind.
'I pronounce it 'Vista'
'No way man it's 'Vista'
'You are both wrong, I pronounce it 'Vista'.