There are quite a few X200M revisions. I'm using current git. As opposed to givemesugarr, hardware accelerated OpenGL works fine for me, but is somewhat slower than fglrx. As does randr (1.2), which makes way for very convenient and quick display configuration changes (my xorg.conf is quite minimal). PowerPlay works too, I guess, at least the driver reports DynamicClocks being enabled. Compiz does not work for me b/c of API compatibility problems, but it did work, although buggy, with code using the old DRI API.
Code:
01:05.0 VGA compatible controller: ATI Technologies Inc Radeon XPRESS 200M 5955 (PCIE) (prog-if 00 [VGA])
Subsystem: Hewlett-Packard Company MX6125
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B+
Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
Latency: 64 (2000ns min), Cache Line Size: 64 bytes
Interrupt: pin A routed to IRQ 17
Region 0: Memory at c0000000 (32-bit, prefetchable) [size=64M]
Region 1: I/O ports at 6000 [size=256]
Region 2: Memory at cc300000 (32-bit, non-prefetchable) [size=64K]
[virtual] Expansion ROM at cc320000 [disabled] [size=128K]
Capabilities: [50] Power Management version 2
Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 PME-Enable- DSel=0 DScale=0 PME-