Paul:
There are many similarities between the links of both countries, the saddest one being that where the links trail
is strongest, those links are becoming progressively more green/lush, thereby diminishing the true links experience for the tourist. A catch-22 situation arises: the tourist wants to play the 'big name' links and by doing so, compounds the problem. The problem is not straight forward; many of the finest links are found in sleepy hollows/villages and towns
and golf is ITS industry - helping to support the population.
To protect from widespread scarring that golf 'traffic' can produce, excessive watering is occuring at an alarming rate. Wise golf tourists with a sense of history and feel for links golf secretly pray for the mean, lean, impoverished fairways of yesteryear. However, these die-hards are only around 20% and so clubs cave in to the 80%. There it is in nutshell: the Augusta National Syndrome spreading its influence to different regions of the globe.
I apologise for getting off the track: now to your question.
While the links in both countries can be either relatively
flat, medium, or mountainous in undualtion, in general, the championship links of Scotland tend to be lower-lying (Old Course, Carnoustie, Muirfield, Turnberry, Troon, Prestwick, North Berwick, Southerness, while many of the best Irish links are more heaving in magnitude. There are no absolutes in this, (indeed several notable exceptions) only trends.
One difference is that while gorse does appear readily on the links in both countries, in general, the Scottish links tend to have a greater profusion of it.
Wee burns are found in both Ireland and Scottish links, but again in general, the championship links of Scotland, plus 2nd tier links are more prone to have menacing burns: St. Andrews, Swilcan; Carnoustie, Barry, Jock's; Turnberry, Wilson's; Dunbar, Roxburn; Cruden Bay, Bluidy; Machrihanish (can't recall name); Machrie (ditto); Leven Links, Scoonie; and another fifty or so.
Forget about any wind comparisons: wind is wind and can destroy your game at any moment on any links. After four trips, I still love the way proud locals proclaim their links ... "the windiest links in all Britain". I heard it so often I am almost deaf to the sentiment!
Both countries could point to several long brutal links. Across the board, though, I would say the Irish ones are longer.
I have generally found the speed of greens to be equally slow in both countries. Coming from Melbourne where the greens can be lightning quick, everything else seems slow.
As a rule, the championship links of Ireland are easier to get a game on, booking wise. Despite this, the Irish links tend to be less crowded.
Have a great trip, a little tip: forget about cramming your itinerary with the championship links; get your fill of these and then get off the beaten track, let your hair down, save valuable cash, and rejoice in the glorious uncertainty of links golf.