since you were recently asking about DIR and are considering going tech, I would strongly recommend to not get the Suunto. The reason is the proprietary RGBM algorithm. For tech diving, imho, you want a computer that runs the same algorithm as the program you use for planning your dives, and the same algorithm that your training agency recommends. That way you get consistent, predictable results. No use in planning the dive and making a deco schedule upfront, and your computer suddenly turns out to have a different opinion (underwater!). Which one will you follow
Plan the dive with DM5, the Suunto planner, and dive the plan. Sorted.
Oh, and you will find that the difference between a Suunto and 50/80 or 50/85 (what I generally dive) is not significant, at least in the normoxic range, I have not been past 60m with a Suunto.
Compare a 50/85 profile with a Helo2 P-2 plan (60m, 25 minutes, 18/45, 50% and 80%) and the run times are 80 and 81 minutes. Plans for the newer computers are similar at P0 while P-2 knocks off 10 minutes, about the same as a /95 plan.
Before you object, the exact stop times at each depth will vary. If diving in a team with different computers it will be like being on different gases, or mixed OC, CCR. If you must line up exactly and not wait for people to clear, then all use the same computer.
I used a Helo2 for a while as a backup to a Petrel on a JJ. Before that the Helo2 was the primary and a Zoop the backup. With a plan on a slate it doesn’t matter bending the Zoop.
You choose whether the computer or the slate drives the dive. The slate plan is important as it reflects the gas, but would you stay longer than the computer says just because the slate tells you to? Were you at the plan depth the whole time?