TL;DR. Two premium $800+ cards from different sides. Sapphire Reserve ($795) is a personal travel card with Hyatt and United transfers, 8x on Chase Travel, and the new Sapphire Lounges. Business Platinum ($895) is a business card with Centurion Lounge access, 5x on Amex Travel flights/hotels, 1.5x on $5k+ purchases, and roughly $1,200 in Dell/Indeed/Adobe/Walmart+ credits. Reserve wins for personal travelers. Biz Plat wins for businesses that actually spend at Dell, Indeed, and Adobe.
The three dimensions that actually decide it. First, personal vs business. Reserve goes on your personal credit report; Biz Plat does not. If credit-utilization management matters, Biz Plat keeps high spend off personal report. Second, lounge access. Both have Centurion-tier or Sapphire-tier lounges. Biz Plat's Centurion access is unrestricted (cardholder); Reserve's Sapphire Lounge access is unrestricted in the new network. Roughly tied. Third, credits. Biz Plat's credits are vendor-specific (Dell, Indeed, Adobe); Reserve's are mostly broad (travel, dining, Apple).
Real customer scenario for each. If you are a small-business owner who spends on Dell hardware refreshes, Indeed job postings, and Adobe Creative Cloud, Biz Plat's credits genuinely net out and the welcome bonus (150k MR) is one of the largest in business cards. If instead you want a personal travel card with broader applicability, Reserve is the right choice.
The trap to avoid. Picking Biz Plat for the welcome bonus then never using the Dell, Indeed, or Adobe credits. The credits are real but require behavioral fit. If you do not buy from those vendors, treat Biz Plat's effective fee as the full $895.