Chinese avionics are quiet good now and on many cases they surpass western avionics
The evidence(of the Chinese having surpassed the Russians) is right there, even Russian officials admit to that. Here's the excerpt I posted earlier from CIDEX(Chinese Defence Electronics expo):
Earlier, the situation was reversed with the Chinese going to the Russians to get components they could out-source.
Gripen's operating costs are around half the F-16's. Our JFT costs ONE-THIRD the F-16's. Senior AF officials, including the Pak AF chief(at Dubai 2012) have publically stated this. Quiet an achievement I'd say, this means pilots get to train more(extra flight hours, lower costs), be more effective, etc.
Where did you hear that? Pakistan chose the J-10 over going for a larger fleet of F-16s, Pakistan's President even sat in a J-10A somewhere in 2003/4. The FC-20/J-10B development was effected by PAF input, and there are dozens of Pakistani aeronautical engineers in Chengdu. @eaglehannan(on a sister Pak defence forum) posted alot of info he got from Pakistani engineers in Chengdu, also talked about how some of them were educated in Chinese aeronautics institutes, while some were educated in British institutes.
So I don't think it's fair to say that Pakistan is getting some "watered down" export version of the J-10.
Also, about the JF17. One of the reasons the aircraft's development costs were relatively low, was that many avionics and electronics researched and developed for the J-10, were "ported" to the JF-17. The KLJ-7 radar on the JF17, is the exact same design as the KLJ-10 on the J-10, except with a smaller T/R dish to accomodate the slightly smaller nose cone. The radar's compatible with the exact same frontline weapons suite the J-10A/B uses. That means it uses the latest Chinese weaponry, like the SD-10B that is superior to the Russian BVR R-77. If you research into it, even western sources like Janes called it roughly at par with AIM-120 C5's(slightly older AMRAAMs).
Aircrafts are complex beasts, combat performance is effected by many different factors and how all these different avionics components perform together. With alot of avionics in the JF17 having derived from the J-10, the only major difference is the bigger engine(0.4 Mach speed difference, Mach 1.8 vs Mach 2.2), and the bigger airframe enables more weight(carries 11 hardpoints vs 7). This stuff comes at a considerable cost though, J-10 costs around 1.5 to 2x what JF17 does(15-25 million USD vs 40 million+). For China(which is one of the biggest countries in the world), J-10's larger range means they can cover more territory with fewer jets. Other than that, they carry the exact same weapons suite, common/derived radar, bunch of stuff is common.
The PLAAF still sees the value in JF17 and CAC officials say PLAAF has been testing the aircraft. It was reported in 2011 that the FC-1 passed some sort of tests and met PLAAF's criteria. They are developing their own WS-13B Turbofan engines for this aircraft though, and I don't think the PLAAF will induct these aircraft with Russian RD-93 engines. They've even begun using their own WS-10 engines on J-11s, J-10s. So anyways, JF17 isn't exactly some small less-performing aircraft either.