I'm in the exact same situation. Paid for customs and taxes, would be delivered yesterday and it's stuck at: customs status updated (31/12/18), but no recent changes.
At least I just received the MandarinEs Symbio W ear tips, and I really like them with my Pinnacle P1 1 IEMs.
One of my big issues with IEMs is getting a good seal, comfort and secure seat.
My favorite so far was a small foam tip that came with the 1More Triples, which provided good seal and good lower frequencies, while still being moderately easy to insert and acceptably comfortable.
The Symbio W are quite firm, and the memory foam prevents the silicone from being deformed when seating them in the ear canal. That makes it easier and more comfortable for me to insert them and they seal very well in the outer ear canal without having to push them uncomfortably deep into the ear.
The sound is much crisper and cleaner with the Symbio W compared to the foam tips, with more energy and clarity, more forward mids and highs combined with a slightly leaner but cleaner and tighter low frequency range. Less forgiving (in the upper frequencies) but really nice with good recordings! They are seemingly combining the crisp sound of silicone tips with the good seal of foam and adding good comfort.
I went back to the other favorite tips with the P1, the Spinfit silicone tips and the comply foam tips.
The difference is quite big, IMHO. I summarized the impressions below:
Comply: "Warm and baasy" more bass, but not as clean, warmer and subdued/muffled mids and highs, less punch
MandarinEs: "Clear, clean and energetic": less bass quantity compared to comply, but clean and tight bass, clear, punchy sound, (much) more energy in mids and highs, more forward.
Spinfit: "Smooth and relaxed, slightly mid centric": slightly less bass than MandarinEs, a little smoother and relaxed, somewhat less clarity and less energy than MandarinEs. Seems more mid-centric with slightly reduced bass and treble (compared to MandarinEs)
Combining these impressions with the opinions about the Kanas and Kanas Pro it makes perfect sense to me that Klaus on Headflux liked the MandarinEs Symbio for the KPE.