I have done some instruments in the R22, hydraulic R44 and the Jetranger. It gets easier as you go up in size
I have also been on a check flight in an A109 in full IMC.
Without doubt I would not like to have to rely on instruments in an R22, very very hard work. Hydraulics and stability reduce the workload by a factor of 10, that’s why they invented SAS’s
I have inadvertantly flown into cloud once in the R44 Raven while trying to climb on top. Over wales with scattered at about 5k I aimed for a large gap between clouds but misjudged the size of the cloud, which is very easy to do. It was a scarey experience for a second but I went instantly onto instruments and setup my scan. I didn’t panic and just flew the aircraft watching the instruments. I knew I would break into clear air any second, it turned out to be about 20 seconds. I certainly wouldn’t want to do it again though. I can see how the fear you first feel as it all goes white could take over and it’s just a matter of time then.
I have since spent some more time with the screens in and an instructor flying with sole reference to instruments so if it ever happens another time but perhaps in less favourable conditions I will be better prepared. The 5 hours you do for the PPL is clearly not enough, particularly in helicopters.