Has anyone with a high risk decipher stayed on Active Surveillance

See if you can get a second opinion with a medical oncologist who specializes in PCa. Urologist can be dismissive about Decipher and other similar tests.

Does "GC2 70/30" mean GG2 (3+4) with 30% pattern 4?

Your age and PSA levels are also relevant, as are any aggressive markers like cribriform pattern or IDC-P. But personally I would not consider AS with 30% pattern 4 and a 0.95 Decipher. Taken together, that's a near guarantee that your cancer will progress (and possibly rapidly as far as prostate cancer is concerned).

You should request your Decipher GRID report. Among other details, it gives a probability of upgrade and I'd hazard a guess that you'd be looking at a high likelihood that your biopsy under-graded your cancer and you'd be upgraded after surgery.

If you're seriously considering AS, then at minimum I'd recommend having your biopsy re-read by another institution like Johns Hopkins, to try to confirm the grading.

Thanks for the responses. Age 70, PSAD .21 PSA 5.7. PIRAD 5. I plan on a second opinion. And will do radiation when the time comes, which is probably right around the corner.