Sorry I am missing something here.
I am told here that the SF4008/HD51 DVB/S2X capability is marketing blurb, although people demonstrate it working, but Vu+ have a S2X tuner and its abilities are not a debateable issue?
Don't believe everything you read. Here can been found lot of fake news.
All the DVB-S2x transponders which are now available in the world works fine on the HD51.
This doesn't mean that in future this is still so. Below you can find more info and make your own conclusions.
DVB-S2x interest to read is follow:
http://www.newtec.eu...s2x-demystified
1. Smaller Roll-Offs
2. Advanced Filtering
3. Supporting Different Network Configurations
4. Increased Granularity in MODCODs
5. Higher Modulation Schemes up to 64/128/256APSK
6. Very Low SNR MODCODs
7. Linear and non-linear MODCODs
8. Bonding of TV streams
9. Additional standard scrambling sequences
10. Wideband Support
HD51 should support all point except point 8 as this is not possible by Broadcom SOC used in HD51.
8. Bonding of TV streams
Other models (like SF4008) claim to have full support DVB-S2x however this tuner fails on many points.
For point 1 I am not sure but specifications of chipset doesn't mention it.
1. Smaller Roll-Offs
6. Very Low SNR MODCODs
8. Bonding of TV streams
10. Wideband Support