I can't really comment on your children, but I know at a similar age my mother made comments about how I had my hands full, and how 'lively' mine were etc etc. I imagine they still have the 'spare the rod, spoil the child' view. Also both my mother and sister only had two children with larger age gaps.
Fast forward a few years, mine are now 7.5, 5.5 and nearly 3. Recently they commented on how nicely behaved mine all were, how well they played together, how nice it was for them to have company of a similar age.
We do do things differently to how my parents and PIL did. FIL still finds it hard to accept that children can chatter at the table for example. We do it differently because of our memories, which is probably why you do things differently, you don't want your children having the same misery you did. The main thing you need to examine is whether you are going too far the other way.
I live by two guidelines in behaviour management-
'don't accept behaviour in a 4yr old that you won't want in a 14yr old' (obviously punishment will be different but if you don't want a 14yr old puttinng spaghetti on walls in cafe then tell a 4yr off for. Doing it - can apply to 2yr old too)
Secondly try to always be 'firm but fair' so in that situation an appropriate approach might be to move them next to you and warn them that another behaviour like that and you will have to leave cafe early before pudding. I don't smack mine, and also try not to give OTT reactions e.g no pudding for a week.
You could e-mail them and say that you have bad memories of your childhood so want to do things differently but that you will monitor your children's behaviour, or you could ignore and in a few years they will probably be better with some consistent parenting - which you might already be doing.