This paper compares unbuffered wormhole-switched networks and buffered packet-switched networks with respect to estimation of expected packet latency. Simulation experiments show that the variance of the natural sample-mean estimator is significantly larger in the wormhole-switched case. An increased estimator variance is an evidence of a harder estimation problem. In particular, it leads to larger confidence intervals. The increased variance is attributed to the in-line blocking property of wormhole-switched networks. This property results from lack of smoothing buffers at the switching points. The overall effect is to increase both the variance of individual latency recordings and also the amount of serial correlation in the sequence of latency samples. The performance of two frequently used variance estimators is assessed in this paper. Estimating variance by assuming independent samples fails for unbuffered networks. A batched-means method do work provided the ba...