BenchmarkDotNet v0.15.8, Windows 11 (10.0.26200.9711/25H2/2025Update/HudsonValley2)
Intel Core i7-8750H CPU 2.20GHz (Max: 2.21GHz) (Coffee Lake), 1 CPU, 12 logical and 6 physical cores
.NET SDK 10.0.403
  [Host]          : .NET 10.0.14 (10.0.14, 10.0.1426.52326), X64 RyuJIT x86-64-v3
  SingleOperation : .NET 10.0.14 (10.0.14, 10.0.1426.52326), X64 RyuJIT x86-64-v3

Job=SingleOperation  InvocationCount=1  IterationCount=12  
LaunchCount=1  RunStrategy=Monitoring  UnrollFactor=1  
WarmupCount=1
Method MeanErrorStdDevRatioRatioSDAllocatedAlloc Ratio
'Raw client: GetItem, then TransactWriteItems (conditional delete + conditional put)'5.714 ms0.2964 ms0.2314 ms1.000.0674.83 KB1.00
'ARX UpdateAsync with AllowKeyChange'6.511 ms1.4933 ms1.1658 ms1.140.2084.39 KB1.13