i have a 91 and 92 range rover classics. i drove a friends 97 disco 1 for a few days and the classics have much better vision "up" in front of you. i found myself having to look under the roof line to see traffic lights in the disco. plus the seat seemed to go lower in the classic.
reliability? yours is a 91 mine is a 91, 205k on mine, just did head gaskets myself, pretty easy, 400$ out of pocket. dunno, seem pretty reliable to me.
http://www.rangerovers.net/index.shtml#introhead
look here for most any info you need. easy to work on, parts aplenty,
but when i started looking into one 6 yrs ago, this was the only site that said " if you need all the warning lights to be out and everything working right all the time look elsewhere"
be careful the bug is hard to scrape off.
motto, " its a land rover thing, you dont have the patience to understand"