Soccertese, below is my experience both current and historic with Requip which may be of interest.
2009-dx, given starter pack and titrated to 6mg and swapped to Requip xl 6mg.
I was happy on 6mg for many years but daytime sleepies was so bad I got a bed for work. I also went from normal sleep to blocks of 6h's through the night.
I tried without success to tolerate 8mg but was thwarted by full on anxiety attacks . As I was now undermedicated I started sinemet cr 50/200 x 2.
I found that when I started levodopa I had no problems and 18 mth ago suddenly tolerated 8mg requip xl.

Now as stated in my first thread and I apologise for repetition, Iv just increased requip xl from 8mg to 10mg for 2 weeks then up to 12mg.
I have now been on 12mg for 4 weeks and there are some motor improvements but the cost is I am now managing to only sleep in 2 hr blocks,it takes far longer for any meds to kick in, the improvement is mitigated by a significant increase in symptoms when the meds wear off with the added highlights of dyskinesia and awful brief episodes of being spaced when I suddenly find myself, for example, staring blankly at the toilet bowl,not moving/thinking for 30 secs or more. All these negative things are new to me and have just appeared and then got worse over the last 4 weeks in direct proportion to the introduction and build up of 12mg Requip xl.

I am now in the difficult position of giving it another week, hoping to ride it out or reduce to 10mg,the last point at which I saw improvement. Either option is a scary prospect.

As an example of how unpleasant these drugs can be for some people and to illustrate how even a low dose can bring on a world of hurt search for drug user reviews such as 'ask the patient' but look for people who have been prescribed Requip for restless leg syndrome because the doses are minute 0.25 - 0.75mg for this condition.

Another aside regarding dopamine agonists is that although they are classed as 'agonists' when you read the manufacturer's professional info they admit they don't really know how they work but think stimulating dopamine production is the most likely mechanism.

It may not be available to you or suitable but Safinamide may provide a filler function as it is a dopamine re-uptake inhibitor and also there was, though It may have fallen by the wayside, Pardoprunox going through trials. This is/was an part agonist part antidepressant. (again this dopamine/serotonin link)
My conclusion is that dopamine agonists are very serious meds indeed.
Just a final thought the various trials and after market studies show alarming volunteer drop-outs for a drug thats approved and given out,at times,like candy. and yet many people benefit with little problem.

I guess that's why our charity ribbon is grey, 'cos nowt's black or white in Parkinsons.

Nigel