Yes cabinet 27 is just outside the exchange and around 1500m away
Speed estimates seem to be 5.8 to 20 Mbps, so smack in the middle. Which estimate did the ISP give you?
ADSL2+ estimates look to be in the 4.5 to 11.5 Mbps region, so a little worse but not amazingly so, so upgrading was always going to be hit in miss in your case.
Latency is not that different for many people on FTTC.
So all in all, about what might be expected. A door or two either direction its a different cabinet and much better speeds
The ISP quoted me 13.5 to 20.5... 11.5 is under the guaranteed speed so can cancel my contract for nothing. The exchange is 1050km away as the crow flies, not sure where you get 1500m from? The strange thing is there are no visible cabs outside the exchange.
There does seem something strange on my line, just reset my router and got the following read out:
xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 1181 Kbps, Downstream rate = 10496 Kbps
Bearer: 0, Upstream rate = 1181 Kbps, Downstream rate = 11618 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
SNR (dB): 2.9 5.9
Attn(dB): 34.6 0.0
Pwr(dBm): 10.6 10.5
Not sure why the SNR has dropped, nor why the max attainable ds rate is lower than the actual rate