At my judo club randori is usually 30-45mins at the end of the session. Some nights we just have randori for an hour and a half. The randori itself usually consists of 5min bouts with no break in between, everyone in the club gives maximum effort, there are no weight classes and most are exhausted after about the third partner change. Is this a good way to practice? I feel that the standard of judo just drops as soon as everyone gets tired and don't believe this is the best way to practice.
If you take a look at BJJ training for example, rolling is never really 100%. In fact it is encouraged not to go 100% so that you can get more out of the practice trying many different positions and techniques each practice until it all becomes muscle memory, rather that just getting stuck in someones full guard for 5mins. I believe judo could benefit with this approach to training for example have randori session were you just go with any attempt at a throw to help your partner work out when it is best to come in for a throw and to help them with their technique. Two people going hammer and tongs at each other for 5mins with terrible technique will not make a good judo player in my opinion.