I've used a SL RG1 which is similiar to the Strato and currently using SL RG4 monobloc. With monobloc, I do get more power, better imaging, can use shorter speaker cable, etc. But, the biggest improvement though, is that each note just seems to flow more free and easier. It's more apparent when listening to dynamic instruments.
If you can afford it, go for the mono bloc. Otherwise, I would probably replace it with a better stereo amp such as RG1, as it might cost less.
If you can afford it, go for the mono bloc. Otherwise, I would probably replace it with a better stereo amp such as RG1, as it might cost less.