The Banbury-based marque certainly appeared to make strides in winter testing, notably given the fact the car now has KERS on board for the first time.
Behind the scenes, however, their driver line-up proved problematic as they were forced to replace their replacement.
In dispensing with the experienced services of Timo Glock, and making no bones about the fact they needed a pay driver, last season's GP2 runner-up Luiz Razia was initially given the call.
The young Brazilian, however, was let down by his sponsors in a move akin to winning the lottery, only to lose the ticket.
With just two testing days remaining, Marussia then turned to Jules Bianchi, whose disappointment in being overlooked for the seat at Force India quickly turned into elation in finally getting into F1.
With the season-opening Australian Grand Prix just days away, Booth said: "Although certain aspects of our winter were quite challenging, the overwhelming feeling we take into the race is great optimism.
"In many ways we are in our best shape ever as a team and everyone is thriving on that and looking forward to what we hope will be a positive 19-race journey ahead.
"Our new package has performed well in pre-season testing, with encouraging signs in terms of performance and reliability, and we also have two very exciting young drivers in the car.
"Whilst they are both rookies, their combined depth of experience rising through the ranks in the junior formulae and in F1-supported young driver programmes leaves them well placed for their debut season.
"It is still too early to fully appreciate the progress we have made for 2013, as that wide picture has a habit of revealing itself in Melbourne, but we are feeling confident in our direction."
Although a rookie, Bianchi's experience as reserve at Force India, as well as in the Formula 3 Euro Series, GP2 and Formula Renault 3.5 now puts pressure on team-mate Max Chilton.
Courtesy of Marussia's driver woes, Chilton enjoyed more time behind the wheel of a new car than any driver throughout testing.
That will at least stand him in good stead, and he is adamant he feels "totally prepared for what lies ahead now".
The 21-year-old from Surrey added: "We gathered a lot of information with the car in Jerez and Barcelona, and at every stage it has been possible to see the benefit of all that learning and development.
"I hope to continue that in the opening races. I think we have a good car for Melbourne, but it is vital we keep pushing forward.
"Overall, as it's my first time in Australia and I've heard so many great things about the place and the atmosphere, it's going to be quite a weekend."