The reliability is doubtful. 100BaseT can be considered as the next step of upgrade. 10BaseT Switching HUB uplink to the 100BaseT HUB, which connects those hosts that need 100Mbps bandwidth. All you can think of. There maybe collisions and traffic jam at the 100BaseT segment.
Network traffic is reduced.
Newer systems will enjoy the top speed at the 100BaseT segment. It is ready for the future. The older system can enjoy the improved lighter traffic at the 10BaseT segment. 10BaseT Switching HUB uplink to the 100BaseT Switching HUB, which connects those hosts that need 100Mbps bandwidth. All you can think of.