I've grown Lemon Spice both ways, and at least in my climate, budded yielded a much more vigorous, productive and longer lived plant. You're correct that some just won't grow own root, while others are such vigorous, vital organisms they'll grow any way you can get them.

Originally, roses were primarily offered only own root, so the roses selected for introduction had to root easily and grow well without "artificial roots". As budding became the norm, that ability didn't matter and many were introduced which either won't easily root, or won't grow well own root. That's still an issue today. J&P began offering their New Generation roses a few years ago, and have been increasing the number of varieties available own root. Henry Fonda was one they offered as a New Generation for a while, until they discovered it wasn't very good own root. At least this spring, it went back to being only offered budded.

My experience has been that MOST roses will grow own root, but MANY won't be as good as they are budded. If you can't get a budded plant of the one you want to grow, try it own root. You may discover your micro climate or cultivation practices you can alter may allow it to be acceptable in your garden. Of course, as long as it's not a patented variety, you can always learn to bud it yourself.

This week, I visited Sequoia Nursery and saw the perfect example of what we're talking about here. Burling Leong, who does the budding and pollinating there, has the old HT Grey Pearl in one of the green houses. There is an own root plant which is a sickly looking, dwarf runt of an example of this rose in a pot. Right beside it is a budded one which is absolutely glorious! The only difference between the two plants is one is budded while the other is own root. It just isn't vigorous enough to be a good plant without the artificial vigor supplied by the root stock.

As more and more roses are offered own root, you're going to find fewer introduced which don't root easily and don't produce as well own root. Another example of "the more things change, the more they remain the same". Give Lemon Spice a change. It is one of three introduced in the 1960s created by Armstrong which are beautiful, fragrant flowers. The other two, which have also been favorites of mine for many years are, Sweet Afton (huge, shell like petals in a blush pink with great fragrance) and Touch of Venus, my favorite white Hybrid Tea (elegant, feminine, fragrant white). Arena Roses offered budded plants of Lemon Spice and Sweet Afton for a few years when they produced roses. Unfortunately, they don't generate new plants any longer, but you may be lucky enough to find budded plants of these two still around in some nurseries. Good luck!