I did my first 10K in September 2011 just as a way of getting fit after major hip surgery and loved the atmosphere that much i decided to do a marathon so went home that night and entered Edinburgh for May 2012. while traing for this i managed to do the liverpool half in 1.49, so set myself a target of 4 hours for the marathon, i managed to keep to my plan right up to the 21 mile and due to the heat that day really slowed but still very happy with my time of 4.12. Again i loved it and was determained to beat 4 hours so did it again this year in 3.52. which was far easier than my first one have since done the Berlin marathon and managed 3.55 and this was after not being able to run for 3 weeks before the race due to injury.
So to answer your question yes you should be able to step up no problem and if you put the training in it will be an enjoyable experience, i would highly recommend Edinburgh
It's been my only one so far so can't compare it to anything but I really enjoyed it. I know the year before they had complaints about the finish and they changed it for last year so thing that is now all ok.
As for not being in Edinburgh you start in the city centre and finish about 6 or 7 miles outside, it is run along the costal road so after the first 10 mile it becomes more countryside going through small towns and villages and had loads of folk out cheering everyone on so I think you will enjoy it.