Manchester Oxford Road gates are in use pretty much all day (but not in the evening when they would be most useful), but the wide gate at the end is always open, and the staff manning it just let folk wander through without even asking for or checking tickets, so it is a fairly pointless waste of money putting them in there. There is no shortage of staff, they just don't seem that interested.
The new gates at Huddersfield, introduced with much song and dance recently, are hardly ever in use at any time - seemingly due to "staff shortages".
Leeds might as well not be there. Again they are normally always in use, even in the evening, with staff in attendance. But, yet again, they normally leave the wide gates open and normally unattended so you can just walk through there unchallenged. The staff are often just milling around chatting to each other. You can also just wander up to the gates and look confused, whereupon a hand will appear and open the gate for you without even asking for a ticket.
Every time I have been through Bradford Interchange they have been open and unattended.
Every time I have been through London Kings Cross they have been open.
Blackpool North, however, seem quite efficient with their gates.