Just a plain, honest answer without sentiments.
Originally posted by C.W Tsorotes Really I'm starting to weigh up whether or not its worth selling my pentax K7, fisheye, 17-70, grip and 540gz and moving over to the Canon 7D.
There is a huge chance you will loose a lot of the money you invested when you sell. See how much this deal will really give you in money terms, calculate how much money you need to add just to the exact same set on Canon. That would give you a cold, hard comparison of whether you can stomach the expense.
Quote: Well more its the choice and market of higher end telephotos and lense choices in general, High ISO work that is concerning me as I want to get more into long exposures, deep sky/star trails.
2 arguments here, higher-end lens choices and high ISO work for long exposures.
I cannot judge your first argument, only you yourself can pinpoint which lenses in the Canon lineup you care for and which do not have a Pentax cousin, quality-wise as well as money-wise.
Your second argument is a mystery to me and I am surprised nobody else hit on this yet: "long exposures, deep sky/star trails" are invariably made with low ISO settings, at least that is the common advice you read and see time and time again. High-ISO requirements could include sports or indoor activity shooting, rough-weather but NOT long exposures!
Quote: The other thing is well the flash system on Pentax isn't reputed to be as good as the Canon....not sure how true that really is? wouldn't say thats an issue for me as I use the 540 and have not had any dilemmas or issues using it.
I'd say that pound for pound Pentax and Canon flashes do not differ that much. If you'd want a real upgrade in flash photography, Nikon would certainly be a smarter bet?
Quote: 1080p with manual control on the 7D.
No idea what your requirements are, but I'd say that anybody is better off buying a HD videocam rather than trying to shoot video with a DSLR. It is gadgetry, at least now. It may someday result in a truly bifunctional camerasystem but for now a videocam doesn't really do good stills and a still camera doesn't take very well to video.
Quote: Finally working professionally I worry I may not be taken as seriously (ok that sounds petty)
It does sound petty. You may gain more professionality points by changing your website, the car you use to drive to customers with, your letterhead paper, the presentation of your work portfolio, pre-labeled DVD's with professional screent-printed artwork etc. It seems to me that the only one who is not taking you seriously is you?
Quote: BUT....reasons keeping me with the Pentax is I love its ergonomics, I already have a kit established and I love the camera itself.
Good, solid reasons. I imagine you could find more.
Quote: Or am I just trading one similar camera for another and just better off getting a 5D Mk2?
Again, compare and see where you experience your gaps are in terms of equipment. Truly, nobody here can tell you you'd be better off with camera A or camera B. All of the cameras you mentioned have tons of info available about them. Search and find the one "must-have" feature in all of them and go for that system.
In the end, you cannot go very wrong with ANY of the cameras you mentioned and that includes your current one!