Adaptive space-time transmission for MIMO channels is considered. In contrast to pure diversity/multiplexing tradeoff, all component modes of the adaptive transmission are designed to enjoy transmit diversity, irrespective of the symbol rate. This is realized by using linear matrix modulators, a.k.a. nonorthogonal space-time block codes. Adaptation between modes with different data and symbol rate is based on a two-dimensional channel quality indicator. The data rate is adapted depending on the received SNR, whereas the symbol rate is adapted depending on the practical channel rank. As an example, the packet throughput of a system with 4 transmit and 4 receive antennas is measured. Different correlation scenarios are considered, ranging from macrocells with very strong correlation between antenna elements to i.i.d. Rayleigh distributed channels