So went and got a TP-Link 9980 to replace the ECI modem on my work line which is a Huawei cabinet and the reason for my slow speeds is obvious immediately.
DSL Modulation Type:VDSL2
Current Rate (Kbps)
Max Rate (Kbps)
SNR Margin (dB)
Line Attenuation (dB)
Looks like banding has been applied and so stuck at 15 Mbps download connection, have had this in the past and it generally improves again after a few weeks so will be interesting to see when it relents.
No point in the more expensive full AC kit, as just having 802.11a on 5GHz is enough to avoid Wi-Fi issues and until G.fast appears not going to be going much faster.
Was a breeze to set-up all I needed to change was username/password and set wireless settings/admin passwords.