Not to beat a dead horse... But no one here can comment on difference of sound signature between e5000 vs. Heaven viii?
Your question made me curious, so I had a quick subjective listen.
- E5000 vs Heaven VIII - H8 has tighter bass, and more detail and transparency. Voices have a extra level of detail that makes the singer more present. The E5K sounds muffled, compared to the H8
- I then tried the AKR02, and had a similar observation, that the AKR02 had another level of clarity that made the H8 sound like it was lacking some detail. The AKR02 sound was a bit harsh, as I had not used it for awhile, but it started to smooth out quickly. Going back to the H8, you noticed the lower detail and transparency. The AKR02's strength is detail, which can make bad recordings unlistenable.
- all 3 had good bass, though with different character.
The Final single BAs are quite amazing for their wide range, from lows to high, coming out of a single BA. The :Lab I with 2 BAs in parallel is quite amazing.
Of course these are not fair comparisons, as the H8 costs 2.5 times the E5K, and the AKR02 is about 2 x the H8.
Any of them are fine earphones, by themselves. You enjoy them for what they are, and compare them to equivalents, and they will beat most similar priced IEMs.
You do get something for the extra money that you spend for the upper models. Final does put more of their magic into their upper models. I guess the components are better, with tighter tolerances, etc.
So the old Final IEMs are still very competitive/musical, and worth getting if you find them for reduced prices.