Sadly for me this just isn't so. This is my 1st play through of LOTRO and it's become apparent to me that I level up much slower than other players. There are players in my kinship that went from lvl 50-60 in the amount of time it's taken me to get to 53. It's not a question of whether I can reach level 60 with my PC in the 4 month window, but whether I'll have the opportunity to level up a 2nd PC too. I just bought the Mines of Moria expansion a month ago (have a policy of only using earned in-game LP for such purchases) and would dearly like to start a 2nd Runekeeper PC. The reality though, is having had to miss about a month of play during the SoA window due to work demands, I didn't manage to break 50 before the MoM unlocked - got in to Moria 5 days late. And trust me when I say, I do play often and for decent length sessions.
I think something players that have played through LOTRO before miss, is that these legendary servers are not classic servers. That means there's a number of game play features that weren't there in the original SoA content, or MoM expansion for that matter. While that does mean a first time player is treated to some nice new content and play features, it also considerably ups the amount that has to be learned. TBH, I've been at times overwhelmed by the sheer volume of the knowledge required to play optimally. If I had one beef so far it would be about the quality of the few in-game tutorials, which IMO haven't been very good. Fortunately there are some true sages in my Kinship to help.

It all means though, that I stick with my one PC as that keeps me closer level-wise with the majority of players and gives me more opportunity to play with groups.
I realize a few years down the road when I finally get to end content I can start a 2nd Runekeeper PC, but that probably means I'll play them mostly solo due to a diminished server pop. I've no doubt I'd level my 2nd PC quicker, so even an extension of the current windows by a couple of months could probably make a difference for me. I'm playing a Lore-master and enjoying the game very much, but admittedly I do feel I'm missing out a bit by not playing another class I'm equally interested in. Anyhow...it's not my intention to wine or demand sympathy, just to give a perspective from a n00b player who's struggling to keep up.