Inspectors said HMP Oakwood, England's largest prison, had a "culture of respectful treatment" and was generally well thought of by prisoners.
However, a series of recommendations for improvement have been made to prison governors.
Officers' use of force against inmates was not always said to be justified.
Inspectors also said they were disappointed with the level of education on offer to prisoners, while some sex offenders had not been given access to any programmes encouraging them to stop offending.
Concerns were also raised around overcrowded cells and the length of time inmates had spent in isolation due to Covid.
The prison just north of the M54 is home to nearly 2,100 male inmates, many of them serving long sentences and is privately run by G4S.
The HM Chief Inspector of Prisons, Charlie Taylor, has called for stronger monitoring of use of force and assessment of inmates' educational needs.
Inspectors said they "were not confident that force was always used proportionately". Around 1,000 prisoners also live in 'double cells' originally designed for one person.
At the time of the inspection in May, many prisoners were still spending up to 22 hours in their cells to try and prevent the spread of Covid, measures which have been criticised as overly draconian by campaigners.
Mr Taylor said overall Oakwood was performing well.
He said: “I was consistently struck by the positive way that prisoners talked about the prison, welcoming the levels of trust that they were given and describing, with very few exceptions, a professional and supportive staff team.
“Even those who were on the basic regime, and were still subjected to protracted time locked in their cells because of Covid restrictions, praised the prison. Many who had spent years moving round the secure estate told me it was the best prison they had been to.”
But he said there were "unnecessary delays in producing any sort of in-cell learning" and "inexplicable delays with the assessment of the learning needs of new prisoners".
"Covid restrictions meant that prisoners at Oakwood were still locked in their cells for too long each day and there was not yet enough access to work or training, but if momentum is maintained, I am confident that the prison will continue to make progress when the pandemic is over."