Thats pretty much the same thing that happened to me lol, ultimate was my first modpack and i fell in love with it
Well, even tho some may marvel at how you "stayed in the past" (lol, but witness Pyure's question as the perfect example), I think you made a terrific choice to stick with your Ultimate world. There is a lot that has changed since the Ultimate 1.4.7 days, but mostly in the magic mods. Since I'm a tech person, and since Ultimate had the "ultimate" tech mod (GregTech of course), I was perfectly happy. Then there was a falling out of sorts, due to Greg's abrasive personality, and things have never quite been the same (in my opinion, probably not shared by all).
Infitech 2 modpack (3rd party pack but private, you have to search out the code for it and don't ask me why that makes any sense at all except it must be because of the whole Gregorious T fallout) is probably gonna be your best choice if you ever do decide to move forward to the present-day with FTB. That pack has GregTech in it, just like Ultimate did. But GT changed quite a bit, mostly due to the oregen which is totally unique. I love the oregen but a lot of people didn't. And Greg never finished that version, he moved on to the next one, leaving others to "patch it up" a bit. And so it goes in the modded minecraft world. LOL