Apples, oranges and peanuts. I would characterize them as follows (from what I've read):
S350DL (= Tecsun BCL3000)
+ Nice size, big controls
+ analog tuning
+ good MW sensitivity
+ AM selectivity as well as FM reception appear to be decent
- Drift on shortwave counteracted by a locking circuit (what about the right way to do that, better temperature compensation?) which *may* be disturbing
- probably still shows all kinds of images and mixing products on shortwave, like the BCL2000 (it's a single conversion rx, and far from the best one)
- audible images on MW
E5:
+ Good all-round performer (all bands) with good frequency stability and selectivity and even decent SSB reception (not quite up to 7600G(R) standards, but then what in this class without a CXA1376 can do that?)
+ Seems to have good audio for its speaker size (big weakness of 7600G/GR); bigger sets with bigger speakers can sound better, of course
+ Little tuning noises
+ Compact and easily carried around
- Some weaknesses in the details (shielding for microprocessor could be better, too simple PLL LPF)
- operation, while much improved over the DE1103, still has a few quirks
- FM not quite overload proof, but still among the better-performing portables in that regard (the Redsun RP-2100 appears to beat it here)
- I don't know whether they finally ship with the new PSU that does not do double duty as an interference (noise) generator
One other model I'd suggest to read up on is the aforementioned Redsun RP-2100, a fairly new model of a fairly new Chinese company that can safely be considered BCL2000/3000 / S350(DL) competition. This is a true dual conversion set on MW/SW with PLL synthesis and 10 memories for each of the 5 bands (MW, SW1-3, FM) which is reported to have excellent audio and good reception on all bands (even though there seem to be some issues with 2nd order intermod on the higher shortwave ranges). Like I wrote, it're reported to be quite immune to FM overload. Has some unique features, too, an IF output for example.. A more fancy RP-3000 with numeric keypad, synch detection, SSB and all appears to be in the works for next year.
I've found a rebranded RP-2100 for a mere 60€ and am now strongly considering buying one. The E5 has been on my list of things to watch out for for a while anyway, to keep my AN-LP1 from being bored to death. (My trusty ICF-SW7600G is nice for SSB, but AM audio is so mid-centric when compared to other rigs - its very own predecessors in particular - that it makes you cry. No comfy listening there.)