I find the my Osker Tombo to be excellent about not having air leaks and single notes easier. The crossover seems to be a bit sharper when played correctly but 7-10 is harder for my to play well with a crossover relative to my Osker harp. Is this me or a Osker being better for single notes and a crossover better for really clean notes but harder to play consistently?
Scott4
Hi @scott4
Thank you very much for the heart-warming, interesting and inspiring PM that you sent to me today. I do not have much time now but will answer it later.
As far as your question concerning your Lee Oskar vs your Crossover, which key does each harp have? If they have different keys, then you will usually notice differences while playing ā even when the keys are close (e.g. one harp is a Bb and the other is an A harp).
If both harps have the same key, then there are numerous factors that still come into play. Perhaps the most important bieng your skill and time spent playing each harp; the reed gaps and shapes; air leaks. 
In general I do not think that one can make a broad statement that Crossover harps are better or worse than Lee Oskar harps across the board, since very minor tolerance differences that occur in manufacturing ā and these are all mass-produced instruments, so there are always differences between one Crossover (or Lee Oskar) harp in Bb and the same one next to it on the sales shelf. Sometimes the differences are large enough to require adjustments on one while the other seems to be perfect out of the box. 
To be explicit: we are dealing with mass production musical instruments that are quite sensitive to tiny differences in tolerances ā and that all for a very cheap price when compared to quality (but also mass-produced) saxophones, guitars, accordions or whatever.
Regards,
ā Slim 
Slim
i could have gotten lucky as my Osker required no tuning nor were there any air leaks. Plates are straight. a plastic comb helps. I think its like a fishing lure. The one you have the most confidence in is the one you catch the most fish with.
Scott
Hi Scott @scott4
And perhaps not so lucky with your Crossover ā that happened to me and I have not tried another one since. I have found several other harps that have mostly been good out of the box ā but there is still variability that sometimes requires me to work on them. Maybe Iām too picky & inflexible 
.
I think you got it !! 
Regards,
ā Slim
Slim
I feel there are very few assembly line harps that do not require and some adjustment. It seems the harp is not very forgiving when air leaks or need for some reed work is concerned. I love my Crossover but it needed to have the reed plates straightened. My Osker was close but the low end reeds were a bit off.
I can tell you a new twin engine Cessna aircraft that may cost well into or more than six figures requires some trim and possibly a bit of adjust to the throttle the keep both engines exactly in sink. No two harps or airplanes are made exactly right off the line the same very often. First thing I do with harps is check to make sure the reed plates are straight and will not cause leaks. Never got one that was spot one at the get go. I cannot complain as if all and to be exactly right the cost would be much higher.
Thanks and hoping your having a good day.
Scott
Your accordions from Lee Oskar seems to have interesting quality.