Okay, I have patched the F3/5 and it is all up and running.
I have a 5402HD M2 as well, so was interested in the differences (if any), here are my very early impressions between the two:
First up and the main difference is the picture quality, the M2 is much better, in fact, even my wife noticed it, on the HD channels there is a lack of definition with the F3/5 whereas the M2 is simply stunning, many people may not really notice but when you compare them side by side there is a distinct difference.
GUI is basically the same on both machines, the F3/5 does have a few more useless additions such as IPTV and a calculator!
There are no lip-sync issues with the F3/5, although I have just upgraded the FW on the M2 to the latest 140p and it seems better than previous so maybe not such an issue now.
The F3/5 has two USB inputs, one on the back and one on the front, whereas the M2 only has the single one on the rear.
No SCART output on the F3/5, shouldn't bother too many people as we all use HDMI now.
BISS and CAS exactly the same i.e. accessed via 8280 and 8281 on both machines.
The tuners seem about the same, probably the F3/5 is slightly less sensitive, a little 'flatter' and more even.
3G modem setting.
No need for the 002 add-on file.
FTP.
On-board user manual as well as printed one.
So, in conclusion, the only real drawback of the F3/5 is the poorer picture quality, that said, I bought mine on fleabay for £95 + £10 delivery to Spain, whereas the M2 cost me £145 including delivery from Amazon.
I will not compromise on picture quality as I am viewing on a 55" Samsung LED TV, but for smaller TVs and 'less-fussy' people it is a really good box.
All opinions expressed are my own.
Intrigued to see what the new 5402HD M3 will be like, hopefully, the picture quality will match the M2.