"Is York considered to be a good uni?".
Most certainly. While I would caution against placing too much emphasis on the dreaded league tables, York is one of only two of the 'Plateglass' universities, established in the 1960s that has consistently appeared in the top 20. The operative word is consistently. Others come and go but York and Warwick remain. Indeed, only yesterday we saw the publication of the Times Higher Education World Rankings for 2020. York was listed as 16 in the UK (world rank 128) while Warwick was 9 (world rank 77). Only Oxford, Cambridge and Imperial were in the world top 10 but all the UK top 20 were in the world top 150.
There was a time when York's standing was sky high. Circa the year 2000 it ranked alongside Oxford and Cambridge in the top three (based primarily on research quality). It gained a reputation (somewhat unfairly) as a university of choice for well off students who had just missed out on a place at Oxbridge - an accusation that nowadays, equally unfairly, is often aimed at Durham (17 and 133 respectively in this year's UK and world rankings). Since then, York and other similar institutions have enhanced their diversity and become less socially exclusive. This inevitably involves welcoming some students whose A level grades are not always the very highest but are taken in context. Nevertheless, academic standards remain among the best in the world.
Research has shown that - Oxford and Cambridge aside - there is little difference in the minds of employers and the wider public between the higher ranking universities in the UK. It is far better that potential students make their choice on the basis of which course, institution and location they will be happy with for three very important years of their lives.