You are comparing two things at very different prices, though. BK-7m can be got for under $1000 new, as far as I can tell, Midjay Plus is about $1700, right (new)?

I like my BK-7m, but think there's a few things the OS needs (that have been added to the BK-9 OS). First is the Mark/Jump for SMF's (if you aren't using this, you aren't getting the most out of your SMF's), second is the Dynamic Arranger (backing gets louder or quieter depending on your playing dynamics), and lastly, it needs the BK Performance editor iPad app to work with it.

Hopefully, Roland can update the OS for these things rather than a new model...

For more forward looking arranger players, a decent WS (Motif, Krone, etc.) married to a BK-7m is quite a potent combination.

Regarding the sounds of the Midjay Plus, do you know these demos?
http://www.ketron.com/sounds.asp?mod=MIDJAY Plus
http://www.ketron.com/sounds.asp?mod=SD2

The second link is for the SD2, but the sounds of SD 2 and Midjay Plus are absolutely identical (statement from Ketron).

I own a BK-7m, all in all its sounds are really good, some are great. Strings and acoustic guitars are rather average. IMO, from what I hear in the demos,in some cases Ketron has an (slight) edge over the BK-7m (maybe some trumpets, saxophones, large strings, acoustic guitar, maybe also drums), but for other instruments it might be vice versa, and the BK-7m has a wider choice of sounds. Given the price difference, the BK-7m seems to have a much better value for money.

I absolutely agree.

As to the price difference, that does not have me worried as I picked up this Midjay Plus for 700 euros
On top of that it is a bit like comparing apples with pears.
I had the BK7m and did not like it. (that is not to say I will like the Midjay, mind you). As far as the arranger section goes, styles, sounds etc. I generally prefer ketron styles to Roland styles and soundwise it is a mixed bag. The Ketron drums were superior to all others imho as far back as 1994 with the Soltom MS50. If indeed the Midjay sounds are fully identical to the SD2 and SD4 I will have no worries really.
Added to that of course the Midjay holds so many more functions than just an arranger. It is a full-fledged midi and audio player, with crossfade functions, supposedly you can ( partly) remove the leading voice in a record for karaoke purposes and it is also a multitrack digital recorder.....or so they say
Anyway I will keep you posted in the future about my findings.

regards,
John

P.S. no one as regards matching it with the Roland PCR-500 and allocating midi functions ?

The new MidjPRO is on stock now, and there already seems to be a first return and B-stock item at www.thomann.de:
http://www.thomann.de/gb/ketron_midjpro_b_stock.htm

No surprises there. Ketron has had a flawless reputation for marketing things with substantial delays, massive bugs and poor servicing. I do not doubt that in the long run this unit will have its merits, but having a touchscreen etc. etc. I would not touch it for the next twelve months or so. That having been said I am well pleased with the purchase of my Ketron Midjay Plus, I guess the fact that I only paid half or less of the original streetprice adds to the satisfaction but still.......it is a very versatile module with a very good soundsource. Playing midifiles on it is really impressive, and I do not even bother because I am using it as a complete arranger keyboard in addition to my KOrg PA800..

regards,
John