A quick check on my Vu+ Duo2 receiver of the transmissions that have moved to HB13G would seem to suggest where I am (County Tyrone, Northern Ireland) that the SNR of the respective transmissions have dropped approx 1db on 13G compared to what they were on 13C.
If that shows to be consistently the case & is the same when HB13F comes into service, then given the transmission parameters that most Hot Bird transponders broadcast with - requiring reasonably high SNRs - then that's a significant fall in the rain fade margin to the point that a Sky (UK) Zone 2 satellite dish probably isn't large enough now to give an acceptable rain fade margin locally except maybe on most of the DVB-S transponders. Essentially that makes Hot Bird reception here needing an 80cm dish at a minimum for reception in all but the typically heaviest of local rainfalls.
I might need to tweak my Zone 2 dish I have for "temporary"** reception of 13 East, but I don't think it's been knocked out of alignment that would cause a 1db fall on its own.
** I say temporary, it's been up now over 18 months! I really need to get the Wavefrontier T90 I have sitting in a spare bedroom out & installed to finish off the dish farm in my back garden & take the two Zone 2 temporary dishes down!
At my place in the southern parts of Sweden almost all signals from 13G are stonger than those from 13C. Some transponders are much stronger and some a little bit. No one is weaker. However I have noticed the strength varies over the day.
11766 V is around 88-89 % (on the VU+ Duo 4K SE) in the morning but in the evening it's 95-96 %. Same thing every day. These variations goes for some other transpoders too. If it's caused by the LNB, the cable or the satellite I don't know. (On the VU+ Duo2 it's 97 % in the morning and 99 % in the evening).
Really strong transponders are 10873 V, 10992 V, 11034 V, 11137 H, 11373 H, 11585 V, 11662 V, 12111 V, 12558 V which all are 99 % 24/7 on the 4K SE. A bit weak (87-90 %) are 11013 H, 11747 H and 12692 H. Might be better with an adjustment of the skew.
However I will make no adjustments of the dish (110 cm Triax) until 13F too is operational and both 13G and 13F has "setteled in" at their new home at 13 degrees E.