Depending on whether you have a Huawei or ECI cabinet, the matching modem is usually the better. But not always.
I have two HG612s. Currently with a 60,000 Openreach banding on my line (dammit) for no good reason, one sync's spot on 60,000 with Max a fraction lower, (odd but common), the other in the high 57,000s with roughly the same attainable as the other. Huawei cabinet.
Now running on a ZyXel VMG1312-B10A which is duff for IPv6 but sync's on the 60,000 again, showing 7.2 or 7.3dB noise margin and attainable 66000+. Roughly in line with what you are seeing, if my cap was removed.
Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk.
Domains, site and mail hosting - Tsohost
Connection - AAISP Home::1 80/20. Sync 60000/15336kbps @ 600m. - IPv4