Some people seem to underestimate Tigerlakes CPU Performance.
There's also quite a few people overestimating it apparently.
Unlike AMD back in 2014-2016 Intel has a Singlethread lead over Renoir, probably quite a big one with Tigerlake, the Willow Cove cores are top notch and superior to AMDs Zen2, the situation with AMD years ago was completely different. As for multithreading they can improve quite a lot over Icelake because of the mediocre clock speeds.
Two problems here. 1 - the difference looks to be under 20% IPC and clock difference is still unknown. 2 - but how power efficient are the CPU cores?
Let's take R20 as an example workload which stresses all cores in a CPU. In a 15W config, Ice Lake
maintains a clock speed of approximately 2.2GHz all-core. Not a bad showing at all, especially when you consider the IPC uplift over Skylake.
But compare this to my dirt-tier r5 3600. At 15W for the cores alone and in R20 they can maintain a clock speed of 3.225GHz on average. (Note: this is not including uncore power, but the fact that it's a 6 core CPU and the sheer difference in clocks should still show it is considerably above Ice Lake in terms of power efficiency).
I don't see Tiger Lake performing particularily well in multi-core tasks compared to Renoir. Improved clocks compared to Ice Lake probably won't make as huge a difference as you'd think, because in the same power limited scenarios (as you should be getting with a -U sku), Renoir will clock much higher.
and it remains to be seen how far ahead 8/16 performs in a power limited U series
See above, I think I've done a good job at showing the 8 cores will be fine. I'd wager most - if not all - 4800U skus will be set to 25W cTDP, so the maintained clocks I mentionned above may be on the table still. If not right there, then close at least. Even at 15W, I doubt we'll be seeing the 4800U drop below it's 1.8GHz base clock with the exception of power-virus-style tests.
Furthermore the iGPU is very important for the U-series because of the ongoing thin and light trend, only a very small percentage of Icelake-U notebooks have a dGPU option.
iGPUs are great, but they're far from important. 90% of people buying notebooks don't care about iGPU perf. There's a lot of stigma around iGPUs, and on top of that... most people just don't care about iGPUs.
If iGPUs were 'very important', Picasso would have sold like hotcakes.
Also, you're only considering 1065G7 devices, of which yes few have dGPUs. But that's not necessarily the case for 1035G1 devices, for example.
I would love for iGPUs to be more important given future things here and there, but the reality is they're not.
I mean if someone really needs excessive multithreading for rendering or software encoding etc, they should go with the 4800U, but the majority won't need this.
The vast majority of people would be fine with an r3/i3, 8GB RAM, an SSD, a 1080p screen and an 7-8 hour+ battery life. Extrememly solid single threaded and iGPU performance aren't particularily important for the vast majority of laptops, because they're used as Facebook/Office machines by most.