I am a very happy Canon user, and love the finder on my New F1 - but, I think with specs you may find the same issues with it as with your OM (which is known for having a great finder to start with - so I think that in itself is not an issue, but rather making it work for someone with glasses). In view of this, I have to wiegh in on the side of the F3hp - every time I look through one of these the viewfinder blows me away. Personally, I think it is the best I have ever seen on a 35mm slr, bar none. And I think the hp would put you right in the ball park for getting around the glasses issue and letting you use that gorgeous, 100% finder!
And yes, that film advance is Rolex smooth, butter feels like scotchbrite by comparison!