After testing the Frontier X2 for weeks, here's my brutally honest take on this premium chest strap monitor that promises lab-grade accuracy.

PROS:

• Continuous ECG is revolutionary - Unlike smartwatches giving spot checks, I recorded 24hr data including sleep arrhythmias my doctor actually used. The live-stream feature (with permanent link) is gold for content creators.

• Strap comfort surprised me - Silicone dots and breathable fabric made it wearable during marathon training. Even survived ocean swims (1.5m waterproof rating holds up).

• Vibration alerts are genius - Custom buzzes when hitting target zones kept me from overexerting. Perfect for HIIT sessions.

CONS:

• Price sting hurts - At $599 + $119/year subscription (for VO2 max analytics), this demands serious commitment. Micro-USB in 2025? Seriously?

• App learning curve - Metrics like "Strain" and "Body Shock" need better explanations. I watched YouTube tutorials to decode my data.

• Battery quirks - The 14-day claim only works if you disable live-streaming. Heavy users will charge every 3-4 days.

VERDICT: If you need hospital-grade ECG tracking during activity (like my triathlete friend with WPW syndrome), this outperforms any smartwatch. For casual users, cheaper options like Polar H10 suffice. The subscription feels greedy, but firmware updates show Fourth Frontier's commitment to improvement.